Micro 4/3rds Photography

What can we expect from the GH3?

2012-02-11T21:35:00.003Z

The Panasonic GH series has comprised the premium camera models for Micro Four Thirds. The Panasonic GH1 and GH2 have had the best video quality among mirrorless cameras at the same time, and they are also considered to have the best sensor for photos. They are not intended to be volume models, but rather to sell at a premium price for those who want the best camera.

Panasonic GH1 (left) and GH2 (right)

The Panasonic GH2 was announced in September 2010. I bought it the very first day it was available in my market, which was in December 2010. Hence, this camera is starting to get old. In this article, I would like to speculate a bit about what we can expect from the GH3.

Timing of announcement

To speculate about when the GH3 will be announced, it is always useful to look back in time, and see when previous camera models were announced.

In the timeline above, the important tradeshows (PMA and Fotokina) are shown as vertical lines. We see that some camera models were announced in connection with these shows, e.g., the G1, GH1, G2 and GH2. However, after 2011, it seems that the announcements are less connected with the tradeshows. The PMA 2011 was cancelled, and the Panasonic G3 would probably have been announced at this event, if it wasn't cancelled.

Some have speculated that the GH3 will not be announced until Fotokina 2012, in September. However, I think that is too late. Panasonic cannot have a top model which is two years old, I think. So the GH3 must be announced before September 2012, I think. The distance between the GH1 and GH2 announcements was one and a half year, hence, I think the GH3 will be announced around March 2012.

Features

And what can we expect from the GH3? The GH series will aim to be seen as the king of the hill in terms of mirrorless cameras. That was fairly easy for the GH1 in March 2009, since the competition did not have any cameras out. Now, however, there is a lot of competition.

Megapixels

The GH2 increased the effective megapixels from 12 to 16. Will the GH3 top this off with even more megapixels? Probably, yes. In an interview, some Panasonic staff were quoted to say that the GH2 got 16 megapixels for marketing reasons, mostly. And the market is back to a megapixel war, sadly. The Sony NEX 7, announced in August 2011, has a staggering 24 megapixels. I don't think the GH3 will top this, but it probably needs to close some of the gap to be seen as a serious competitor in the market. So I would guess the GH3 will be announced with around 20 megapixels.

If true, this is mostly bad news. I don't think many need more than 12 megapixels anyway, and increasing the megapixel count even more probably means that other aspects of the sensor cannot be optimal, e.g., noise characteristics and dynamic range. But we see a trend towards more megapixels across many segments now. The new Nikon D800 will have a staggering 36 MP on a full frame sensor. The Nikon 1 system is the only good news in this respect. They "only" give 10 MP, which is probably a sensible figure given their smaller sensor area.

Video modes

Both the GH1 and GH2 supplied full HD video modes with 1080 lines. The GH1 could only do this in interlaced mode, and the GH2 improved upon this by adding progressive modes.

The next big thing in video is 4K. Not very well defined, but 4K means that the horizontal resolution is around 4000 pixels. With the 1080p modes of the GH2, the horizontal resolution is only 1920 pixels. So 4K is a big step up from the GH2.

Personally, I don't think the new camera will provide 4K. It is simply a too big leap at this point in time. The new Nikon D4 flagship model does not provide 4K, and still has 1080p as the largest video mode. Rather, I think the GH3 will further refine the video at 1080p, and possibly add higher frames per second modes.

Autofocus

All Micro Four Thirds cameras so far have used the Contrast Detection Auto Focus (CDAF) method. This involves jogging the lens focus back and forth until the contrast is deemed high enough to assume that the focus is optimal. With the current cameras and lenses, CDAF have given fast enough autofocus for still images, even in fairly dim lightning.

This is different from DSLR cameras, which use Phase Detection Auto Focus (PDAF). PDAF is better at following moving targets, which CDAF currently does not do very well.

The Nikon 1 system combines the two focus methods, and employs a hybrid CDAF + PDAF method. In theory, this should be able to give better focus for moving subjects, and also to keep the focus better during video recording.

The GH2, while currently probably still the best Micro Four Thirds camera for video, does not do moving targets very well, neither in photo or video mode. So how can the GH3 improve upon this? My guess is that the improvements will be incremental. I think that adding PDAF, like the Nikon 1 system does, is a too large step at this time. There may also be patent issues hindering Panasonic from implementing this. So my guess is that the GH3 will employ faster and better image processing to improve on the autofocus during video recording, but it will not employ any dramatic change to the focus technology.

Global shutter

All Micro Four Thirds cameras so far use a "rolling shutter". This means reading off the sensor values sequentially vertically. For still images, this is just fine, but if the subject moves during exposure, it could give some strange artifacts. We can see this as buildings "leaning" to one side if you pan horizontally during video capture, or rotating propellers warp in a strange way. I have compared the rolling shutter artifacts of the GH1 and GH2 here.

To fix this problem, Panasonic could implement the "Global Shutter". This would involve reading off all sensor values at the same time. Implementing this would mean that they could drop the mechanical shutter. It exists mostly to avoid the rolling shutter artifacts for still images. Hence, it would make the camera less noisy, less expensive to manufacture, and less prone to mechanical failure. Global Shutter would be a huge improvement to the camera.

So can Panasonic implement Global Shutter for the GH3? In an interview before the GH2 was launched, a Panasonic employee was quoted to say that Global Shutter could not be implemented until at earliest in the GH3.

My guess is that a true Global Shutter can not be expected with the GH3. But perhaps they can make the rolling shutter quicker, and avoid most of the artifacts so that dropping the mechanical shutter becomes possible.

Ergonomics

The GH2 improved upon the ergonomics of the GH1 quite a bit. For example, it moved the control wheel from the front to the rear, and added a focus lever on the left shoulder. I would not expect any significant changes to the ergonomics with the GH3 model. There are not many major ergonomic issues with the GH2 anyway.

Materials

Both the GH1 and GH2 employ a plastic shell over a stainless steel frame. Currently, there is a trend towards using more metal as the shell material. For example, the recently announced Olympus OM-D E-M5 has a metal exterior, as do most of the competitor system's cameras. Personally, I think that a metal exterior for such a small camera only serves to give a "premium feeling", and not provide any real value beyond that.

So I would hope to see that the GH3 retains the plastic bodies of the predecessors. But just as the megapixel count, the body material might be important from a market perspective. Perhaps it becomes impossible to sell a plastic body camera, in which case Panasonic must change their strategy.

Conclusion

This article has been mostly speculations, of course. My guess is that the GH3 will present some evolutionary changes to the GH2, just as the GH2 did when it was announced in September 2010.

On the other hand, if the GH3 does not offer 4K video, no major improvements to autofocus during video, no global shutter, then how can Panasonic still claim that it is a premium video enabled model? It could be that they need to step up and give at least one of these features, to differentiate against the other M4/3 camera, and, not least, the competition.

Canon G1X, sensor size the same as GH1

2012-02-08T22:08:00.002Z

The Canon PowerShot G1 X was announced recently, and took a lot of people by surprise. While Nikon have launched their mirrorless, large sensor cameras in the Nikon 1 series, not many rumors existed about Canons mirrorless competitor. It turns out that their answer was a large sensor compact camera, without interchangeable lenses.

The sensor size was also a bit surprising: Larger than Four Thirds, but smaller than APS-C. This sounds like an odd sensor format. But is the sensor format really that odd? Let's try to have a closer look at it.

We know that the Canon G1X sensor is reported to be 18.7mm x 14mm. The Four Thirds sensor size, on the other hand, is somewhat smaller at 17.3mm x 13mm.

But the Panasonic GH1 and GH2 have employed oversized Four Thirds sensors. This design choice was implemented to get the same diagonal field of view in the 16:9 and 4:3 modes, utilizing the full image circle also for video. The Panasonic GH1 has 4000x3000 pixels in 4:3 mode, and is 4352 pixels wide in 16:9 mode. This means that the width of the sensor must be 17.3mm x 4352 / 4000 = 18.8mm. Which is rather close to the reported width of the Canon G1X sensor.

What about the vertical size? The GH1 sensor is reported to have 14 megapixels in total, which corresponds to a vertical resolution of 3217 pixels. Hence, the vertical size must be 13mm x 3217 / 3000 = 13.9mm. Again this is very close to the reported height of the Canon G1X sensor.

And the total resolution of the Canon sensor? 4352x3264. Again, this is very close to the GH1 horizontal resolution times the estimated vertical resolution based on the total 14 megapixel resolution. This can be illustrated like this:

Both sensors are of the CMOS type, and both have a base ISO of 100.

My conclusion is that the specifications of the Canon PowerShot G1 X sensor are remarkably similar to the Panasonic GH1 sensor. This doesn't mean that they are identical, though. But given that there are not that many sensor manufacturers out there, and certainly not for the Four Thirds sensor size, I would say this is a good indication that Panasonic do in fact produce the sensors for the Canons G1X. As you understand, this is of course purely speculation.

A fundamental difference between the two cameras is that the Panasonic GH1 only gives you a maximum resolution of 12 megapixels for one single exposure, with the option of changing the aspect ratio with the same image circle.

The Canon G1X, on the other hand, gives the full sensor resolution output for a single exposure. However, when using video (16:9 aspect ratio), only a smaller image circle is used, meaning that the effective focal length changes.

Why buy a system camera, and why buy a compact camera?

2012-01-30T22:00:00.004Z

If you're looking for a small camera, there are basically two choices. You can go for a small, interchangeable lens camera, for example based on the Micro Four Thirds standard. Or from one of the competitors, like the Nikon 1 system, Sony NEX, and so on. The other choice is to buy a compact camera without interchangeable lenses.

The main difference between these two camera types is the sensor size. Interchangeable lens cameras tend to have larger sensors than compact cameras. There are some exceptions to this rule, though, for example the Pentax Q system, which has a small sensor in a camera body with changeable lenses, and the Canon G1X, which has a large sensor in a fixed lens camera body.

I recently acquired the Olympus TG-310, a compact, rugged camera with a small sensor, for use when swimming, skiing, and so on. And I was interested in seeing what the real world difference between this camera and my Panasonic GH2 is. The two cameras are shown below, with the Olympus TG-310 to the right:

As mentioned, system cameras and compact fixed lens cameras tend to have different sized sensors. To illustrate that, here is a comparison of the relative sensor sizes of the Four Thirds sensor and the 1/2.3' sensor in the Olympus TG-310 compact camera:

The smaller sensor means that the camera manufacturer can cram more features into the lens more easily. So while the Lumix G 14-42mm kit lens seen on the GH2 above only has a 3x zoom and no macro mode, compact cameras tend to have much a larger zoom ratio, and a macro mode to boot. I write about this difference in the introduction to my Micro Four Thirds lens buying guide.

The specific compact camera still has fairly unimpressive optical features, though. This is because it is a rugged compact, designed to be waterproof, shockproof and freezeproof. Because of this design choice, it has a relatively small lens assembly, to keep the size and weight down. This dictates employing only a 4x zoom ratio.

I bought the camera very cheaply, since it has recently been obsoleted by the newer Olympus TG-320. It appears to share some components with similar cameras from Panasonic, most notably the Lumix DMC-TS10.

Looking at some of the specifications of the two cameras used in this test, we see that they are not altogether that different:

System	GH2 + Lumix G 14-42mm	Olympus TG-310
Effective Megapixels	16.1	14.0
ISO range	160-12800	80-1600
Focal length range (equiv)	28-84 (3x)	28-102 (3.6x)
Aperture range	f/3.5-5.6	f/3.5-5.9
Minimum focus (normal)	0.3m	0.6m
Minimum focus (macro)	N.A.	0.03m
Image stabilization	Optical	Sensor shift

But these are just the specifications. Let's see what the difference is in terms of image quality.

Landscape photo

I started with taking a basic landscape photo. I set both cameras to full auto, which is probably what a newbie would do. The zooms were both set to the widest setting. The cameras were handheld. Here are the two images, scaled down a bit, click to enlarge:


GH2, ISO 160, f/4.0, 1/160s	TG-310, ISO80, f/3.5, 1/60s

To compare them better, here are some 100% crops from the images:

While the scaled down images look fairly similar in terms of image quality, it is very clear from the 100% crops that the GH2 in fact has a huge advantage in terms of resolution.

Indoor photo with flash

To further look at the image quality differences, let's look at some images taken indoor with the built-in flash. The subject here is the LEGO Technic 9392 model. Again, I used full auto on both cameras.


GH2, ISO 160, f/5.2, 1/60s, f=33mm	TG-310, ISO100, f/4.7, 1/60s, f=11.8mm

We don't need to look at any crops here, we immediately see that the GH2 image is vastly better. One thing to note, though, is that more of the model is in focus from the Olympus TG-310. It has a deeper depth of focus. This is due to the smaller sensor, which keeps more of the subject in focus. This effect can be both positive or negative, depending on what you want.

Night photo

Finally, I have tried to take night exposures with both cameras. I put them on a tripod, and still left them in full auto, at the widest setting. Here are the results:


GH2, ISO 160, f/5.6, 6s	TG-310, ISO100, f/3.5, 1/30s

In this case, the GH2 noticed that it was on a tripod, and gave me a long exposure of 6 seconds, straight from the full auto mode. This surprised me positively, I had guessed it would push the ISO up to expose it as much as possible during a short shutter time. It also stopped down the aperture to f/5.6, for better depth of focus, and set base ISO. Well done! Just what I would have done myself.

The Olympus TG-310, on the other hand, illuminated the scene with the flash, which gives a pretty good exposure of the handrail in the foreground. But the rest is pitch black.

For the sake of fairness, I gave it another chance, and turned off the flash, while still using full auto. Here is the result, at ISO320, f/3.5, 1/4s:

This image is barely usable, but still much worse than the results from the Panasonic GH2.

Conclusion

A compact camera can be small, cheap, and sport an impressive zoom and macro range. But the image quality tends to be much worse than an interchangeable lens camera with a larger sensor. Of course, there are enthusiast compact cameras too, with a somewhat bigger sensor than basic compact cameras, better and faster optics, and better image processing. But in demanding situations, they still cannot compete with larger sensor cameras.

Another item to point out is the ergonomics. The GH2 is a fairly small interchangeable lens camera, and some complain that the buttons are difficult to operate, being so tiny. But the Olympus TG-310 has even smaller buttons, and requires more dexterity to be operated. It also has fewer buttons, and requires more menu access to change common settings.

Camera bag for Micro Four Thirds: Lowepro Munich 100

2012-01-26T18:21:00.003Z

For a long time, I have tried to find a camera bag which is suitable for carrying the Panasonic GH2 with one small lens mounted. However, I have not found such a bag. I even tried to make my own bag, but it was not very successful, honestly.

But I think I have found a suitable bag now. It is the Lowepro Munich 100:

The bag comes with a slim strap, and a segment with velcro, which can be used to divide it into sections. If using the bag for the Panasonic GH2, or a similarly sized camera, there is no space for extra sections in the bag, though.

And that is exactly what makes this bag good for my use: My camera fits very snugly into the bag. It is probably the smallest bag which can accommodate it with a prime lens. The bag can be seen below, with a Panasonic GH1 and the Lumix G 20mm pancake lens:

But not only a pancake lens fits into the bag. The camera with an Olympus M.Zuiko 45mm f/1.8 also fits well, as does the Lumix G 8mm fisheye lens. But the Lumix G 14-42mm is too large. And it is difficult to bring more than one lens in the bag, together with the camera.

The bag comes with a slim strap, and I don't like it very much. I prefer a sling type strap, to wear the bag diagonally on the back, and easily be able to pull it to my chest for access. I plan to retrofit such a strap, which should be an easy task.

One could ask: If I only plan to bring one lens with the camera, why use a bag at all? I find that a bag is good to have for protection. If it starts raining, the bag will save the camera and lens. And in my area, it is generally below 0°C during winter. The camera is not harmed by this temperature. But the problem is when you bring the camera indoors after it has been exposed to freezing temperature. Moisture will condensate on the outside and inside of the camera and lens, which will, of course, damage it. So leaving the camera in the bag until it has reached a warmer temperature is a good protection when going from outdoors to indoors during winter.

Camera sales statistics from Japan

2012-01-10T19:41:00.007Z

BCN Ranking produce camera sales statistics from Japan of many kinds. The most interesting, from my point of view, is the category "interchangeable lens cameras". This includes DSLR cameras, typically sold as kits, and mirrorless cameras, including Micro Four Thirds, Sony NEX, Samsung NX, and so on.

Here are the yearly statistics of the 20 most sold models in this category, with 2011 to the right:

To make the statistics more useful, I have compiled it into categories, given by the lens mount. Keep in mind that the percentages are taken from the 20 most selling models only (for 2008-2011):

There is a lot to comment about these statistics. Regarding the big two, Canon and Nikon, Nikon had a smash hit with the D40 in 2006. But since that time, Canon has taken over the leading role.

Pentax were also rather large with the K10D in 2006, offering good features at a reasonable price, but has not been able to retain the same market share since. Their newer models have not had the same combination of value for money and features, in my opinion.

Sony launched their DSLR series aggressively in 2008, and got a very healthy initial market share. Two years later, they repeated the same strategy with the mirrorless Sony NEX system, getting pretty much the same market share.

Micro Four Thirds, of course, has grown quite well in Japan, and are now quite close to Nikon in terms of market share. M4/3 is much more successful than Four Thirds ever was. Olympus has three models on the top twenty list in 2008, but their DSLR models have never since made any significant market impression.

The Panasonic G10 was probably intended to be a volume model, with a low retail cost. Perhaps Panasonic hoped to get a Nikon D40 like hit with it. However, we see that it did not reach the to 20 list at all, and that may be why it was discontinued rather soon.

Also worth noting is that Canon have had two models on the list for three consecutive years: The Canon EOS 5D Mark II and the Canon EOS 7D. This shows that Canon have been able to design camera models that stay relevant and desireable for a long time, however, I anticipate that both are due for a replacement in 2012.

Lumix X HD PZ 45-175mm f/4-5.6

2011-12-31T16:26:00.009Z

The new, compact tele zoom Panasonic Lumix X HD PZ 45-175mm f/4-5.6 has a long name, indicating a lot of improvements over the existing value tele zoom Lumix G 45-200mm f/4-5.6. In this review, I have mostly been comparing the lenses head to head. I think this makes sense, since most users will be choosing between them, and hence would like to know how they compare, and if the newer lens is worth the premium price.

Lumix G 45-200mm f/4-5.6 (left), Lumix X PZ 45-175mm f/4-5.6 (right)

Specifications

Lens	Lumix G 45-200mm	Lumix X 45-175mm
Weight	380g	210g
Length	100mm	90mm
Diameter	70mm	62mm
Filter thread	52mm	46mm
Minimum focus	1.0m	0.90m
Maximum magnification	0.19x	0.2x
Lens elements	16	14
Lens groups	13	10
Exotic elements	3 ED	2 Asph, 2 ED
Diaphragm blades	7	7

Based on the specifications, it is easy to see that the newer lens looks more interesting. It is smaller, lighter, has more exotic lens elements. The only negative item is that it has a shorter zoom range. However, the difference between 200mm and 175mm maximum extension is barely significant.

Aperture range

In the specifications, it looks like the two lenses have the same aperture range. And they do have, f/4-f5.6. However, when looking at the aperture as a function of the focal length, it is easy to see that the new lens in fact has a less impressive maximum aperture for all focal lengths between the start and end-points:

This means that the new lens not only gives a slightly shorter zoom range, it is also a slower lens on average. However, I guess that lenses like this tend to be used in the very shortest and very longest settings the most, so this might not be big issue.

Physical, Power Zoom

The most striking difference between the lenses is of course the size and weight. Beyond that, the newer 45-175mm lens has the all-black "premium design", associated with the Leica branded lenses from Panasonic. The older 45-200mm lens has the "common design", featuring a grey ring around the base of the lens.

Another fundamental difference between the lenses is that the new lens has power zoom (PZ), and also internal zooming. Internal zooming means that the lens doesn't change shape during focal length change. The old lens, on the other hand, extends when zooming towards the long focal length range, which is very common for tele zoom lenses. Internal zooming makes the new lens feel very solid. There is no wobbling front section, unlike the older 45-200mm lens.

Power zoom is a feature mostly included for video use. Zooming smoothly manually during video recording is pretty much impossible. But with motorized zooming, it is possible to zoom while recording a video. On a personal note, I think that zooming during a video capture almost never looks good, and is best avoided. But at least the new lens makes it possible to do this with a better result.

For still image use, power zoom is not needed. And some would even argue it is a nuisance: You have better and more precise control with a manually operated zoom ring. However, I find the implementation of the motorized zooming to be very good. There is the option of zooming using a broad, rubberized ring, or using the switch on the side. Using the ring for zooming feels almost like using a mechanically coupled manual zoom ring. There are two exceptions: The zoom ring does not stop when reaching the end of the focal length range, and you cannot see the focal length by looking at the position of the ring. Rather, you must take a look at the display to see the actual focal length.

When using the zoom ring while recording a video, it has the advantage of smoothing out the zoom movement for you, so that the zoom action becomes more even. Using the zoom lever makes the zooming even more smooth. It is possible to operate the motorized zoom at different speeds using the zoom lever, by pushing it more or less hard. This works well

The rubber zoom ring feels a bit thicker and more generous than the old lens. Also, the focus ring feels a bit more dampened than the old lens.

Autofocus

I have tested the autofocus, and compared it with the older 45-200mm lens. I found the autofocus to operate a bit faster than the old lens. The old lens is also very fast focusing, so this is a good achievement.

As with other Contrast Detection Autofocus (CDAF) systems, the focus accuracy is very good. Unlike Phase Detection Autofocus (PDAF), calibration of the lenses and camera bodies is not needed. However, as with all other long lenses, you must take care that the camera focuses on what you want to have in focus. Even if the aperture is not very large in the long setting, f/5.6, the depth of focus (DoF) is still narrow enough that you may experience to focus on a background object rather than the subject. So make sure you understand how the autofocus modes work, and consider using centre spot mode to have full control over what comes in focus. This is important when using the lens in the longest tele zoom extension.

Autofocus while zooming

The older Lumix G 45-200mm f/4-5.6 lens is not optimal when it comes to keeping the focus when zooming. It is clearly not parfocal, and loses the focus immediately when zooming. The longer Lumix G 100-300mm f/4-5.6 is somewhat better in this respect, but still has this problem.

With the newer Lumix X 45-175mm lens, this is still a problem. When zooming during video recording, I've found that it can keep the focus fairly well if the background is static. However, with excessive subject movement or camera shake, the focus can wander off for an extended period of time. In general, you can not expect tack sharp focus until around one second after you stop zooming. This will take longer if the lens is zoomed in.

Here is an example showing how zooming while video recording can look using the two lenses:

As you can see, both lenses fail to focus perfectly while zooming. However, the newer lens generally does a bit better. Also, it is easier to zoom smoothly using the new lens. Especially when using the zoom lever. An added benefit is that keeping the camera stably is easier when using the motorized zoom through the lever.

I could find examples where the new Lumix X 45-175mm lens also fails to retain focus while zooming. This would typically happen if there is excessive camera shake, much subject movement, or very close distance. Closer distance is more challenging for the lens, especially at a long zoom.

Sharpness

When comparing the sharpness of the two lenses, it is hard to find much difference with low contrast test images. This can be seen here, in my first sharpness tests. However, with high contrast images, for example with back light, I've found the new lens to be consistently better. It has less Chromatic Aberration (CA) artifacts, and less flare.

I would say that the newer Lumix X 45-175mm lens is generally sharper wide open. When using a Panasonic camera in auto mode, it will almost always choose to use a long lens like this wide open, so the wide open performance is important.

Bokeh

The term bokeh denotes the rendering of out of focus areas, which can vary a lot between lenses. I have looked at the bokeh of the two lenses by using a high contrast night image as an example. The focus is set on the foreground, which is about 1m away. The focal length was 45mm in both cases. Here are the full images:


Lumix G 45-200mm	Lumix X 45-175mm

Looking at some 100% crops from the top right region reveals that the bokeh from the newer Lumix X 45-175mm is not optimal. The out of focus hightlights are rendered as non-round discs off the centre:

The problem of non-round out of focus renderings becomes smaller as the lens is stopped down. In low contrast situations, this is not an issue at all, since you wouldn't see the bokeh discs as clearly as here.

Optical Image Stabilization (OIS)

Just like almost all other zoom lenses from Panasonic, this lens features optical image stabilization (OIS). Based on my experience, this appears to be effective both during still image photography and video recording. It is almost impossible to video record stably at 45mm and longer focal length without a tripod, so OIS is pretty much needed for video.

In online forums, there has been much discussion about the effectiveness of the OIS with this lens. I cannot see how I can test this scientifically, and hence my advice is: If you are worried about the rumored dysfunction of the OIS, then don't buy the lens. My personal opinion is that this problem, if it is a problem, is way overrated in online forums.

Example images

Here is an example image taken at 45mm, f/4.0, ISO 160, 1/60s, OIS on, handheld:

And a crop from the centre of the image, not re-scaled or sharpened:

This image was taken at 175mm, f/5.6, ISO 320, 1/50s, OIS on, handheld, but with the camera supported against a railing:

And a crop from the middle of the image, not re-scaled or sharpened:

And this image was taken at 175mm, f/5.6, ISO 1600, 1/400s, OIS on, handheld:

And a crop from the top of the image, not re-scaled or sharpened:

Example video

This video was recorded handheld with the GH2. The zoom was set to about 60mm.

I think the OIS system does a good job of keeping the image stable. Compare it with a video recorded using the Olympus M.Zuiko 45mm f/1.8 non-stabilized portrait lens. In the video recorded using the MZD45, I was not able to handhold the camera sufficiently stable.

Conclusion

The newer Lumix X 45-175mm lens is a good improvement over the existing Lumix G 45-200mm lens. It is better optically, and much more compact and light. It also feels more solid, without any extending section when zooming. The power zoom (PZ) implementation is well done, and works fine also for still image use.

While some of the specifications are better than the old lens, it should be noted that some are also worse. The new lens has a slightly shorter zoom range, and is about 1/3 stop slower in the middle of the zoom range. Out of focus renderings of highlights are non-round outside of the centre of the frame. This is mostly a problem only for night time photos. The bokeh is quite good in daylight situations, when the contrast is lower.

So which lens should you buy? If you are interested in video use, then I think it makes sense to get the newer Lumix X 45-175mm lens, since it generally gives you better footage, and allows for smooth zooming while filming. The new lens could also give better image quality for stills use. All in all, I think it comes down to how much you want to spend, and how much you value the compactness. Both lenses are certainly good.

AF speed comparison, Lumix G 45-200mm vs Lumix X 45-175mm

2011-12-29T09:23:00.001Z

The Lumix X PZ 45-175mm f/4-5.6 has the "HD" designation, and it does have the newer "X"branding, indicating that it is a premium lens. I have already seen that it performs better in terms of optical qualities than the older Lumix G 45-200mm f/4-5.6 lens. But what about the focus speed?

I tried to put a figure at about 1 meter distance, close to the minimum focus distance of both lenses. Then I timed the focus. The camera had just been turned on, meaning that the lens is at "close to infinity" focus at the start of the experiment. There is a fair amount of light, with daylight coming in through a window.

Here are the results:

And in a table:

Focal length	Lumix G 45-200mm	Lumix X 45-175mm
45mm	0.24s	0.18s
max	0.54s	0.42s

Conclusion

In my tests, the newer Lumix X PZ 45-175mm does focus faster than the older Lumix G 45-200mm lens. The older lens was very fast focusing already, so this is a good achievement.

Sharpness of Lumix G 45-200mm and Lumix X 45-175mm

2011-12-20T20:40:00.001Z

I have previously tested the sharpness of the Lumix G 45-200mm and Lumix X PZ 45-175mm lenses. My test images then were fairly low contrast, and not too challenging for the lenses. To put them to a more difficult test, I've tried to test them head to head with a backlit subject. This is taken at approximately infinity focus, which is perhaps not the most realistic usage of these lenses.

Lumix G 45-200mm (left) and Lumix X PZ 45-175mm (right)

@ 45mm

The first set of images are taken at 45mm with both lenses. I used the Panasonic GH2 at ISO 160, and a tripod. The shutter speeds were fast. This is what the whole frame looks like:


Lumix G 45-200mm @ 45mm f/4	Lumix X 45-175mm @ 45mm f/4

Here are 100% crops from the centre:

And from the left corner:

I've also made a similar comparison at maximum zoom extension. First, the full images:

@ 175mm and 200mm


Lumix G 45-200mm @ 200mm f/5.6	Lumix X 45-175mm @ 175mm f/5.6

Here are 100% crops from the centre:

And from the left corner:

Conclusion

While my first test indicated that the lenses were fairly similar in terms of sharpness, these tests, taken at more challenging lightning, show a consistently better performance from the newer Lumix X PX 45-175mm f/4-5.6. The newer lens shows less Chromatic Aberration (CA) artifacts, and a better sharpness in the corner, especially in the longest zoom reach.

Lumix Leica 25mm f/1.4 and clicking sounds

2011-12-14T21:18:00.001Z

The Lumix Leica DG Summilux 25mm f/1.4 is a premium large aperture prime lens for the Micro Four Thirds system. It is designed to work as a "classic" bright normal lens for a 35mm SLR system, which was typically rated as 50mm f/1.4. With the 2x crop factor associated with the 4/3 format, the Leica 25mm f/1.4 lens becomes equivalent to a classic normal lens in terms of field of view.

Many users have complained about clicking sounds when using this lens. This has left them worried: When they buy a premium lens, they expect it to function smoothly.

First of all: Don't worry, the clicking sounds are completely normal.

Having said this, let's look at why you experience these clicking sounds.

What's causing the clicking sounds is the change of aperture. In normal operation, the camera leaves the aperture at its largest value when using the camera, and only stops it down just before taking a picture. The aperture is opened up again afterwards. Since the sound of the shutter is louder than the actual aperture change, you don't normally notice the sound of the aperture changing.

I have examined the loudness of the aperture change with a number of lenses here. Generally, most lenses have a similarly loud aperture change. The Lumix G HD 14-140mm superzoom is marketed as a video lens, and is supposed to have more silent aperture change than usual.

However, the Lumix Leica 25mm f/1.4 is the brightest Micro Four Thirds lens so far. When using the camera, it is seeing the outside world through the lens, and relaying the information to you through the LCD screen, or the viewfinder. Unlike your eye, which is very flexible in terms of the dynamic range it can see, the camera sensor can only see a more limited range of brightnesses. When using a bright lens like the Leica 25mm, in combination with a bright surrounding, the light is simply too much for the sensor to process. It needs to stop down the aperture to show you a sufficiently good viewfinder image. Stopping down the lens causes a clicking sound.

Further, the camera cannot accurately focus with the lens stopped down. When stopped down, the depth of focus (Dof) is wider, hence the lens appears to be in focus in a large focus distance range. And this can cause misfocus.

So before focusing, the camera must open up the aperture fully, and then close down again afterwards, if the surroundings are very bright. Both opening up the aperture and closing down cause the clicking sounds. Hence, every time you focus the lens in a bright light, you will experience the click before and after the camera has achieved focus.

If you operate the lens in a dim environment, you should not normally experience the clicking sounds upon focusing the lens.

This can happen with any Micro Four Thirds lens, even relatively slow zoom lenses, given that you point the lens towards a strong light source. But since the Leica 25mm f/1.4 is unusually bright, it happens more often with this lens.

So to conclude: The clicking sounds are a normal part of the lens operation.

Sharpness of Lumix G 45-200mm and Lumix X 45-175mm

2011-12-12T23:08:00.014Z

Note: Since this test, I have done another one in a more challenging lightning.

The Lumix G 45-200mm tele zoom was one of the first Micro Four Thirds lenses launched. It is a value tele zoom, and as such, it does a good job. It does indeed provide good value for money. But it is often seen not too sharp, especially in the longer end of the zoom reach.

A newer version of the lens was launched in 2011, the Lumix G X PZ 45-175mm, with Power Zoom (PZ). It also sports a number of other innovations, for example non-extending zoom action, and nano surface coating. But does it improve on the original tele zoom lens in terms of sharpness?

Lumix G 45-200mm (left) and Lumix X PZ 45-175mm (right)

I have tried to answer this by photographing a simple test setup with the Panasonic GH2 camera on a tripod, using the Panasonic FL360 flash unit for illumination. The flash was angled up towards the white ceiling to spread the light better. The ISO was set to 160, and the shutter speed to 1/60s.

1st series of tests

Here are the two shots at 45mm, from each lens. These images were scaled down and resharpened:


Lumix G 45-200mm @ 45mm f/4	Lumix X 45-175mm @ 45mm f/4

The focus distance was about 1 meter. A distance of one meter at 45mm focal length corresponds to taking a headshot portrait picture. In both cases, I set the focus point on the centre beer bottle logo.

Let's look at enlargements for a better view (the older Lumix G 45-200mm in the top row, and the new Lumix X 45-175mm in the bottom row):

I also tested them in the same way at maximum magnification. In this case, the focus distance is about 2 meters. Here are downscaled versions of the whole images frames:


Lumix G 45-200mm @ 200mm f/5.6	Lumix X 45-175mm @ 175mm f/5.6

And here are 100% crops from the images taken at maximum zoom extension:

Using the flash for illumination has a great advantage: It freezes the image, and camera shake is no problem. On the other hand, the flash cannot quite illuminate the subject sufficiently at f/8, which makes those exposures a tad bit darker. If I had angled the flash towards the subject, rather than up into the ceiling, this would of course be no problem. But having the flash face the subject would create a reflection effect, which is not good for this comparison.

Conclusion

At 45mm, there is not a huge difference between the lenses. In this experiment, they are quite comparable, I would say. In the longest zoom reach, I would say the newer Lumix X 45-175mm lens has somewhat better clarity wide open at f/5.6.

Perhaps it is a bit unfair to compare the old lens at 200mm with the new lens at 175mm, but I believe this is how people would typically use them: When you need a long reach, you usually zoom to the very end.

2nd series of tests

Again, the focus distance is around 2 meters. This time, I use the ambient light, at ISO 160. The shutter speeds were around 1s. To avoid camera shake, I used 2s shutter delay. That way, any shake induced by pressing the shutter is allowed to calm down before the image is taken.

A centre focus point was used.


Lumix G 45-200mm @ 45mm f/4	Lumix X 45-175mm @ 45mm f/4

Here are 100% crops from the centre of the image:

And from the lower left corner:

Conclusion

The second test shows that both lenses are pretty much equally sharp in the centre at 45mm. It also confirms the conclusion from the first series of the test: The newer Lumix X lens is sharper in the corner part of the frame. It also appears to handle flare somewhat better. Perhaps the hyped "nano surface coat" is actually doing something for the image quality.

Macro spacer rings for Four Thirds

2011-11-25T23:57:00.004Z

There are a lot of accessories you can buy for your camera. Since I have a Four Thirds standard lens, the Olympus Zuiko Digital 50mm f/2 1:2 macro lens, I decided to buy some Four Thirds macro rings to extend the macro range of the lens even further. To use the lens on a Micro Four Thirds camera in the first place, and adapter is needed. The Panasonic DMW-MA1 or Olympus MMF1/MMF2 adapters should do. The macro spacer rings then go between the adapter and the Four Thirds lens.

The rings

These rings cost US$10, including shipment from China, which is very cheap. Upon arrival, I noticed that the quality did appear rather poor, in line with the price. The box is rather anonymous, with a "OM4/3" text and something in Chinese:

In the picture below, they are all screwed together, to give the longest possible extension:

And below, I have unscrewed them into individual components:

From left to right: The ring that goes into the adapter, or into a Four Thirds standard camera, and the first extension ring (1, 7mm), the second extension ring (2, 14mm), the third extension ring (3, 27mm), and finally the ring on which the lens is mounted.

By using these rings in different permutations, extensions of 17mm (just the front and rear ring), 24mm, 31mm, 38mm, 44mm, 58mm and 65mm (all the rings) are possible. The 24mm extension, using only the first extension ring marked with a 1, corresponds pretty much to the Olympus EX-25 Four Thirds extension ring at 25mm.

Operation

When using these rings, please note that they have are no electrical contacts at all. This means that the lens is "dead" when mounting it onto the macro extension rings, and you cannot operate the focus or the aperture.

I'm guessing that it is best to first extend the focus of the lens all the way, and then mount it on the extension rings. To do this, you must do a small trick, namely to first manually focus the lens to the minimum focus distance while it is mounted to the camera, and then unmount it without turning off the camera first. That way, you can mount the lens on the extension rings while the focus is already at the closest. Most likely, you'll want to use a smaller aperture than f/2, and again you must do the same trick: Change the aperture and unmount the lens without turning off the camera first. Of course, this process is rather awkward if you are going to experiment with different apertures.

The results

So how do these extension rings affect the close focusing possibility of the ZD50 1:2 macro lens?

First, let's see how close it can focus without any extra extension. Here the lens is mounted to the 4/3 to M4/3 adapter, on the Panasonic GH2 camera:

And the resulting image, at f/8, ISO 160:

24mm extension, 1:1 macro

Using the 24mm extension, corresponding roughly to using the Olympus EX-25 macro extension, the setup looks like this, note that the figure is closer to the front lens element:

With this resulting image, also at f/8 and ISO 160. This corresponds to around 1:1 magnification:

65mm extension, 2:1 macro

Finally, adding all the macro rings for a total of 65mm extension yields this setup:

Note that the figure is now very close to the front lens element. It is not easy to light the figure properly in this position, since the lens casts shadow over the subject. The resulting photo looks like this, at around 2:1 magnification, also written as 2x:

Conclusion

These macro extension rings were cheap, and not very good quality. Further, since they have no electronic contacts, they are very awkward to use. You must stop down the aperture before mounting the lens on the extension rings, which makes focusing harder. Normally, you focus at maximum aperture, and then stop down for taking the picture, which is handled automatically by the camera. But with no communication between the camera and lens, this is no longer possible.

The Olympus EX-25 extension rings allow for changing the aperture, and is probably much easier to use. However, it is also much more expensive.

At full extension, the macro rings allow for roughly 2:1 macro magnification, meaning that you can photograph an object with a diameter of half the diameter of the imaging sensor.

If you want to increase the magnification of a Four Thirds lens, but don't want to shell out the cash for the EX-25 extension ring, I would recommend that you simply crop the center of your images, rather than buy these cheap rings. The rings are not very fun to use, due to the lack of electronic contacts, and the poor quality. Keep in mind that since these rings are for the Four Thirds format, they cannot be used for Micro Four Thirds lenses. They can only be used for Four Thirds lenses.

Olympus 45mm f/1.8 review

2011-11-20T11:47:00.007Z

The Olympus M.Zuiko Digital 45mm f/1.8 is a much anticipated lens. When it arrived, it closed one of the major gaps in the Micro Four Thirds lens lineup: The portrait prime lens.

Appearance

The lens is fairly compact, with a 37mm front lens thread, and is significantly smaller than the other 45mm prime lens, the Panasonic-Leica 45mm f/2.8 1:1 macro lens. They are shown below:

Panasonic 45mm f/2.8 macro (left), Olympus 45mm f/1.8 (right)

Sadly, the lens does not come with a hood. You can buy a hood from Olympus, which is rather expensive, and fits into the bayonet threads under the silver front ring. I chose to buy a collapsible rubber hood with a 37mm screw thread. It cost around US$12 including shipment from China. In the picture below, I have removed the silver ring, revealing the black bayonet mount, and mounted the third party hood:

As far as I can tell, the lens itself is constructed out of plastic materials, has a metal mount, and has polished metal exterior. I know this is a subjective thing, but my opinion is that the appearance is very cheesy. I would have preferred a matte black plastic exterior, which I think is better. I'm looking into ways of making the lens less obtrusive, perhaps using black electrical tape to cover the metal surfaces is a good idea?

Focus

Just like most Micro Four Thirds lenses, the Olympus 45mm f/1.8 has internal focus. This means that there are no moving mechanisms on the outside, beyond the focus ring, and the lens feels solid. This is in contrary to the Lumix G 20mm f/1.7 pancake lens, which has a traditional focus mechanism which moves the entire lens assembly back and forth, making the focus relatively noisy and slow.

The focus ring moves smoothly, and feels like good quality. I could have wished for a rubberized focus ring, though, as the metal is not as ergonomic to use. But I don't see myself using the focus ring a lot anyway, as the autofocus works well.

The autofocus is very fast, and virtually noiseless. I have compared the focus speed with the Panasonic-Leica 45mm f/2.8 macro lens on a Panasonic GH2 camera, and found that in generous lightning, the Olympus lens focused a tad bit faster. In low light, though, the Panasonic lens focused faster, which surprised me.

The focus timings of the Olympus lens in good light are a little bit slower than the kit zoom lenses. See the comparison here for some reference numbers. However, keep in mind that the Olympus 45mm f/1.8 requires a lot more focus accuracy than a kit zoom lens at 42mm f/5.6, due to the much larger aperture. Considering this, I think the Olympus 45mm f/1.8 focus timings are very respectable.

When it comes to autofocus performance during video recording, I've found the lens to be comparable with the Panasonic-Leica 45mm f/2.8, which is to say, not very good. With a moving scene, it can take some seconds before the lens regains focus during video capture, which can be very annoying. But I suspect this is much due to the camera, and that future advances in CDAF and image processing will make continuous autofocus better in time.

The minimum focus distance is 0.5m. While this does not sound very impressive, when comparing with other portrait lenses, it is in fact rather good. The classic 85mm f/1.2-1.8 portrait lenses generally have a close focusing distance of 0.8-0.9m. If used for a headshot portrait, this makes sense, since around 1 meter is the distance needed to fill the head into the frame at this field of view. Nikon's newly released Nikkor 85mm f/1.8G portrait prime lens has a close focusing distance of 0.8m, which is not as good as the Olympus lens.

Image stabilization

The lens features no optical image stabilization at all, just like all other Olympus lenses. When used on an Olympus camera, you get the sensor shift image stabilization, which is effective for stills capture. During video capture, though, there is only digital image stabilization available, which I am told does not work too well.

On a Panasonic camera, there is no image stabilization at all. So for still images, you should try to use a shutter speed of 1/100s or faster to be fairly sure to avoid camera shake when handholding the camera. For video recording on Panasonic cameras, there is no image stabilization available, and it is quite simply difficult to handhold the camera stably during video capture.

In this example, I have recorded a video with the Panasonic GH2 and the Olympus 45mm f/1.8 lens. Believe it or not, but I am doing my best to hold the camera stably, holding the viewfinder towards my eye. To my defense, I can say that I had just gotten off my bicycle during my daily commute to work, which could explain my somewhat shaky hands:

Image Quality

I have made some image quality comparisons with the Panasonic-Leica 45mm f/2.8 (PL45) here. It must be said that all the comparisons are not optimal, since the focus point is not always exactly the same. However, I think this shows that the Olympus lens does not have any significant vignetting.

The Olympus lens does, however, have some Chromatic Aberration (CA) artifacts when the aperture is larger than f/2.8. I also think that the PL45 performs better at f/2.8 in terms of image quality, although the differences are small.

I have tried to do another image quality comparison. To avoid the problem of different focus distances, I chose a subject that was fairly flat, a car registration plate. I focused on the "P" in both cases. The focus distance is about 1 meter, which corresponds to a headshot portrait distance for this focal length. Here is the whole scene, the images are rescaled and sharpened:


PL45 @ f/2.8	Olympus 45 @ f/1.8

Looking at 100% crops to better evaluate the sharpness, I find this:

From the left middle part:

From the right hand lower corner:

In this comparison, it looks like the sharpness is comparable in the centre of the image, while the PL45 performs somewhat worse in the corner. I would like to add that this comparison is not as challenging for the lenses as my previous one was. The examples with trees rendered against a bright sky are much more challenging for the lenses, due to the high contrast.

All in all, I think the image quality is quite good. There is little vignetting, some CAs at apertures larger than f/2.8, and the sharpness is quite respectable for a large aperture lens.

Bokeh

My sharpness comparison also included some bokeh examples. As far as I can see, the lens does not have any problems with the bokeh. It renders the background nicely blurred when it is out of focus, at all apertures. And out of focus highlights are even and rounded.

One thing to look out for, though, is that the aperture diaphragm blades are not as rounded as on the Panasonic-Leica 45mm f/2.8 1:1 macro lens. This means that when stopped down, the out of focus highlights get a slightly more jagged edge.

Example image

Here is an example image:

I used the Panasonic GH2, and the image parameters are: ISO 160, f/2, 1/10s. I focused on the front wheel. The camera was handhold, without any support. How come the image is sharp, with a shutter speed of 1/10s? Because I also used the onboard camera flash. The flash is very quick, and freezes all movement. However, it has a fairly short effective distance, so only the front part of the truck is lit by the flash. The rear part is lit by ambient light, and the tail lights from a passing car.

Since the rear part of the car is out of focus anyway, a bit of blurring due to camera shake during the 1/10s shutter time doesn't matter.

Compared with the Panasonic-Leica 45mm f/2.8 1:1 macro

So, which 45mm prime lens should you get? The Olympus M.Zuiko Digital 45mm f/1.8 (MZD45) or the Panasonic-Leica 45mm f/2.8 1:1 macro (PL45)? If you want to take macro images, there is only one choice, the PL45. However, if you are on a tighter budget for a macro lens, you could also consider the Olympus 35mm f/3.5 1:1 macro lens (Four Thirds standard, not Micro Four Thirds). For this lens, you will also need an adapter, e.g., the Panasonic DMW-MA1 or the Olympus MMF1/MMF2. This combination will have poor autofocus performance on Micro Four Thirds cameras, but some people prefer manual focus for macro use anyway.

If you are looking for a traditional portrait prime lens capable of selective focus and good bokeh qualities, I think the MZD45 makes the most sense, since it has the largest aperture. However, I personally think that the f/2.8 aperture of the PL45 lens is sufficient for a portrait, given that you can plan the background a bit. So either lens should get the job done most of the time, in my opinion.

For video use, the Optical Image Stabilization (OIS) of the PL45 comes handy. Holding a 45mm lens stably while recording video is not easy, and the OIS does give some help. So if you intend to use the lens for video as well, you may want to consider buying the most expensive of the two, the PL45.

Conclusion

This lens comes with a fairly reasonable price tag, especially in Europe, which makes it a must buy lens for people interested in portrait photography and selective focus.

The image quality is good, and the focus speed is fast. The lens is not so well suited for video recording, due to the lack of optical image stabilization. Also, when recording videos, it can be a good idea to prefocus, and then turn off autofocus before starting the recording. The continuous autofocus performance during video recording is not so good, especially in poor lightning.

GH2, ETC mode for macro video

2011-11-19T10:42:00.001Z

The Panasonic GH2 has a very interesting feature, the ETC, Extra Tele Conversion mode. This is like a digital tele zoom. However, when used with videos, you still get the full resolution, with the centre of the sensor being used. This drawing illustrates the concept:

With this feature, you can record full HD videos with an effective 2.6x tele effect, with 2.6 being the fraction 2800/1080. Using the ETC mode, the Lumix G 100-300mm f/4-5.6 tele zoom lens gets an effective 1560mm maximum tele reach, in 35mm film camera equivalents.

However, this effect can also be used for even more enlargements when using a macro lens. Using the Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 macro lens gives you an maximum enlargement of 1:1. Using the ETC mode gives you a maximum of 2.6:1, which is very impressive. Keep in mind, though, that this only makes sense with videos, not with still images.

I have illustrated this effect with a macro video recording of my own eye. The following footage shows the same scene without and with ETC:

It was recorded using the "Manual Movie Mode", 1080p24, f/5.6, 1/25s. To get a sufficient exposure, I used ISO 1600.

As you can see, the depth of focus (DOF) is very thin, and it is difficult to keep my iris in focus. Setting a smaller aperture, e.g., f/8, would help here, but that would require an even higher ISO. And in my experience, there is significantly more noise with ETC mode compared with the ordinary video mode, especially at high ISO.

Focus speed, PL45 vs MZD45

2011-11-05T13:46:00.009Z

There are two competing 45mm prime lenses in the Micro Four Thirds lineup. The Panasonic Leica 45mm f/2.8 macro lens and the newer Olympus M.Zuiko Digital 45mm f/1.8 portrait lens. While one is a macro lens, and the other could be categorized as a portrait prime lens, they can of course be used for a wide variety of other tasks.

I have previously compared the sharpness of the two lenses in various settings. While the comparisons are not always optimal, and could even be a tad bit misleading, I think it is clear that the Panasonic lens is a little bit better in terms of sharpness. This is not really surprising, since a large aperture lens contains more optical compromises, and usually cannot have the very best sharpness. As a general rule, one does not buy a large aperture lens for the optimal sharpness, but for using it wide open or near wide open, in which case sharpness is usually not the main concern.

People generally say that the Olympus M.Zuiko Digital 45mm f/1.8 features faster focusing. But is it true? The Olympus lens is rated as Movie-Still-Compatible (MSC), which means that the focus speed should be quite good.

I have compared them head-to-head in the same setup. The Panasonic GH2 camera was set up about 60cm from the subject, and I selected centre spot focus. The Olympus lens has a close focus distance of 50cm, and the Panasonic lens has a selectable focus limiter, which cuts off at around 50cm for better focus speed.

When powering on the camera, the lens is focused around infinity. Upon pressing the shutter release button, the camera focuses, and then takes the picture. I measure the time from the camera notes that the shutter release button is pressed, until the camera is ready to expose the image. The first event can be noted by the number of remaining frames being shown in the lower right part of the LCD display, and the latter by the green dot appearing in the upper right corner of the display.

Light background, daylight

Here is the comparison in daylight, the lightning was about EV7.

The focus speeds are rather similar:

PL45, focus delimiter off: 0.32s

PL45, focus delimiter on: 0.32s

MZD45: 0.26s

Dark background, dark room

And another test at EV2, which is very dark:

In this test, the Panasonic-Leica lens focuses faster:

PL45, focus delimiter off: 0.68s

PL45, focus delimiter on: 0.66s

MZD45: 1.12s and 1.08s (two tests)

Conclusion

	light	dark
PL45, limiter off	0.32s	0.68s
PL45, limiter on	0.32s	0.66s
MZD45	0.26s	1.08s, 1.12s

As people have been saying, the Olympus M.Zuiko Digital 45mm f/1.8 lens is indeed faster in terms of autofocus. But only by a small margin. And in dark conditions, to my surprise I found that the Panasonic-Leica 45mm f/2.8 lens focused faster.

This is just some few simple measurement, and in practical use, the experience might be different. During the time I have used both, I have generally found that the autofocus speed is comparable between them for practical, daily use.

Generally, the speed readings here are quite good. I have previously seen that the Panasonic kit zoom lenses achieve focus speeds of around 0.17s to 0.33s under similar conditions. But keep in mind that a much higher degree of focus accuracy is needed for a large aperture lens at f/1.8 than the kit zoom lens at 42mm f/5.6. With this in mind, a speed reading of 0.26s is in fact a very good achievement.

For video use on the Panasonic GH2, it is my opinion so far that the Olympus 45mm f/1.8 is better at keeping the autofocus correct during video capture. With the Panasonic 45mm f/2.8 lens, it generally takes more time before the focus is reached when there is movement in the image frame. But this is just my feeling so far, I haven't examined it in a scientific way.

The Olympus lens also appears to have a more silent autofocus operation.

Olympus vs Panasonic @ 45mm

2011-10-27T17:31:00.009+01:00

The long awaited portrait prime lens for Micro Four Thirds is finally here. Olympus has launched their M.Zuiko Digital 45mm f/1.8 lens. It is compact, fairly light, relatively cheap, and focuses quickly and noiseless.

Before this lens was available, the closest we had to a portrait lens for the Micro Four Thirds format was the Panasonic Leica 45mm f/2.8 macro lens. While this lens is a good macro lens, it has not been very well received as a portrait lens because of the not so impressive f/2.8 maximum aperture.

Panasonic 45mm f/2.8 macro (left), Olympus 45mm f/1.8 (right)

How do these lenses compare when it comes to sharpness? I have made some tests to find out. The images were shot using the Panasonic GH2 camera, at base ISO 160, on a sturdy tripod, and with OIS turned off for the Panasonic lens. The Olympus lens does not feature any OIS.

Infinity focus

These images were taken at a focus distance of around infinity. The sun is in the upper left corner of the image frame, which makes for a challenging situation for any lens. A strong light source in the image frame can easily lead to flare, loss of contrast and chromatic aberration (CA) artifacts.


PL45 @ f/2.8	Olympus 45 @ f/1.8

Let's take a closer look at some 100% crops from various parts of the image frame. Here's from the centre:

And from the upper left corner, where the contrast is the largest:

And finally from the top right corner:

10m focus

These next set of images were taken at a focus distance of about 10m. These images were rescaled and sharpened. You can click on the images to see them in a larger size.


PL45 @ f/2.8	Olympus 45 @ f/1.8

For better evaluation of the sharpness, I have made crops from the centre of the image. These crops are taken at 100% magnification, meaning that one pixel in the image corresponds to one pixel from the camera. Click for an enlargement:

And here are similar crops from the extreme top right corner:

0.7m focus

And to complete the review, I have also compared the sharpness at a closer focus distance. In this case, the focus is placed on the centre of the ball, which is at approximately 0.7m distance (about two feet). A portrait distance is typically at 1m or more.


PL45 @ f/2.8	Olympus 45 @ f/1.8

And the crops from the centre:

To evaluate the sharpness based on these is probably not so easy. But the image series can be used to look at the out of focus rendering (bokeh):

Just to satisfy my curiosity, I also took these images at f/16. Due to diffraction, you would normally not use such a small aperture, since it will lead to some dullness at pixel level. But if you need a deep depth of focus, and are planning to publish the image on the web, I would say that it could be a reasonable balance between DOF and image quality to use f/16.

Night scene

Here is a night scene. The focus is set on the middle of the branch:


PL45 @ f/2.8	Olympus 45 @ f/1.8

Some closeups of the out of focus rendering of highlight on the top, right corner:

And from the left side:

Conclusion

So, which lens is best in terms of sharpness? I think that the Panasonic lens generally does better. The Panasonic lens appears to render a bit better at f/2.8, in my opinion. At larger apertures, there is no comparison, of course, since the Panasonic lens cannot be opened further.

The Olympus lens does exhibit quite a bit of dullness at f/1.8 and f/2. On the other hand, it could be that the DOF is too thin for this comparison, even at a focus distance of 10m. So the subject for this comparison was perhaps not entirely perfect.

At the largest apertures, the Olympus lens does show some chromatic aberration (CA) artifacts, both in the centre and in the corner. You can see that near objects have a purple outline, while far objects have a green outline. This is quite common, and can be seen also for the older Olympus Zuiko Digital 50mm f/2 macro lens. When stopped down to f/2.8, CA artifacts are no longer a problem.

The Panasonic lens does not exhibit any significant CA artifacts. Perhaps this is because the CA artifacts are removed in software post processing? I have tried to examine this by looking at uncorrected RAW images and JPEG images, and concluded that there are probably no software correction with the PL45.

I think it looks like flare affects the Panasonic lens the most. This is not surprising, since flare is generally a larger problem the more lens surfaces the light passes through. And the Panasonic lens has the most complicated optical design, with 14 lens elements in ten groups, while the Olympus lens has nine lens elements in eight groups.

The Olympus lens does not exhibit much vignetting. The Panasonic lens, on the other hand, has a bit of vignetting wide open, which goes away at f/4. Again, this could be due to software correction to the Olympus lens, I don't know.

The bokeh appears to be effective smoothing the background, but my daylight example image was not very challenging for the lenses. With higher contrast, at night, the out of focus rendering is not perfect for either lens. The discs are non round off-center for the Panasonic lens: They are elliptical when the lens is wide open. The Olympus lens gives pretty round discs wide open, but they have a tad bit more tacky edges when stopped down, due to the aperture blades not being as rounded.

The Olympus lens is cheaper and faster than the Panasonic lens. But the larger aperture comes at the expense of worse image quality wide open. At f/2.8, they are pretty comparable, but the Panasonic lens perhaps has the upper hand by a small margin. Despite these findings, the Olympus lens does appear to give a good value for money. For users looking for a portrait lens, or a moderately long and fast prime, this is the only choice at the moment.

Bokeh comparison @ 200mm and 300mm

2011-10-22T10:47:00.006+01:00

I like the long tele zoom Panasonic Lumix G 100-300mm f/4-5.6. It is unexpectedly sharp, considering the price, and generally fun to use.

However, after some use, I see some examples where the background blur is a bit distracting. The bokeh some times exhibit a bit of ringing, which means that it doesn't blur the background as effectively as one could wish for.

I decided to test the bokeh with some out of focus highlights. To do this, I photographed the same subject using three lenses, the Panasonic Lumix G 100-300mm f/4-5.6, Nikkor 200mm f/4 AIS, and Panasonic Lumix G 45-200mm f/4-5.6. The three lenses are shown below:

The Nikkor 200mm f/4 AIS lens in the centre is shown including the adapter needed to connect it to a Micro Four Thirds camera.

@ 200mm

The images were taken at dusk, with the camera on a sturdy tripod, and focused on the tree about 2 meters from the camera. I used ISO 160, the base ISO for the Panasonic GH2 camera. As I took the images late dusk, the lightning changed quickly, and they may have different exposure.

Here are the images, click to enlarge:

Lumix G 45-200mm @ 200mm f/5.6

Nikkor 200mm f/4

Lumix G 100-300mm @ 200mm f/4.9

I have made some enlargements as well. These are 100% crops from the centre of the images.

Bokeh

Based on this study, I cannot see any problems with the bokeh of these lenses. They all look just fine. One problem with the Nikkor 200mm f/4 AIS lens, though, is that the aperture diaphragm blades are not rounded. Hence, when stopping down, the lens gives nine-sided out of focus discs, they don't have a rounded edge:

Sharpness

When it comes to the sharpness, the crops above are not suited for comparing the sharpness across the lenses. The Lumix lenses support autofocus, of course, and after viewing the images on PC, I noticed that the camera has prioritized to get the edge of the tree in focus. When focusing the Nikkor 200mm lens manually, I focused on the centre of the branch. So they are not comparable. However, after looking at the images, my conclusion is the same as before: The Panasonic Lumix G 100-300mm f/4-5.6 is significantly sharper than the Panasonic Lumix G 45-200mm f/4-5.6 at 200mm. The Nikkor 200mm f/4 lens appears to sit between them, in terms of sharpness.

@ 300mm

The Panasonic Lumix G 100-300mm f/4-5.6 is my only lens capable of doing 300mm focal length. So I don't have anything to compare with. But here are a couple of images taken at 300mm f/5.6 and f/8:

Again, the bokeh looks just fine, no perceived problems here.

Conclusion

While I believe the Panasonic Lumix G 100-300mm f/4-5.6 is prone to giving slightly distracting bokeh in certain cases, I could not reveal any in this simple test.

We see clearly that the Nikkor 200mm f/4 AIS lens has non-circular out of focus rendering when stopped down, due to non-rounded aperture diaphragm blades. This is not so good for the resulting pictures.

I think that this simple test illustrates another example that legacy lenses are not perfect for use on modern cameras. While the lens is reasonably good in terms of sharpness, the primitive aperture makes it problematic when stopped down. In a previous study, I saw that the Pentax FA50 f/1.4 normal lens exhibits quite distracting bokeh between f/1.4 and f/2. The whole point of getting a fast legacy normal lens is to use it pretty much wide open, and that example shows that it can be non-optimal for such use.

So take care if you buy older manual lenses for use on Micro Four Thirds: Do some pre purchase research to make sure the lens fits your needs.

Sharpness comparisons @ 100mm and 200mm

2011-10-05T19:55:00.004+01:00

Panasonic has got several Micro Four Thirds lenses that span the tele focus range, with the Lumix G 45-200mm f/4-5.6, Lumix G HD 14-140mm f/4-5.8, and Lumix G 100-300mm f/4-5.6 being three of them. The last one is the recently announced powerzoom capable Lumix X PZ 45-175mm f/4-5.6.

The Lumix G 45-200mm f/4-5.6 is a value tele zoom lens, with a useful focus range reaching from the typical portait to long tele area. It gives a good value for money for those who want to try out the tele range.

Marketed as a video optimized lens, the Lumix G HD 14-140mm f/4-5.8 is in fact versatile superzoom lens for photo and video use alike. It is large, expensive, and generally regarded as being very good.

The largest of the three, the Lumix G 100-300mm f/4-5.6, is a very long tele zoom, useful for various event photography, like spectator sports, birdwatching, safari, and so on. For this use, the price is in fact rather reasonable.

The three lenses are seen below:

But how do their sharpness compare? To try to answer this, I've tried to compare them where they overlap. In this experiment, I put the camera on a sturdy tripod, shot at ISO 160 with the Panasonic GH2, and used a delayed shutter to avoid camera shake. I also turned off OIS. I set the white balance to "overcast" for all the images.

I left the exposure at auto at all time, and sadly, the exposure turned out to be slightly different for some of the images. That's a bit negative for this comparison, but I think we can live with it.

Sharpness at 100mm

Here are the full images shot at 100mm, scaled down and sharpened. Click for larger images.


Lumix 45-200 @ 100mm f/4.7	Lumix 100-300 @ 100mm f/4	Lumix 14-140mm @ 100mm f/5.8

To better compare the sharpness, let's look at 100% crops. I have not applied any sharpening to these 1:1 images. These are taken from the image center. Click for larger images.

As it was a bit windy, I recommend that you don't look at the leaves to evaluate the sharpness. They may be negatively affected by motion blur due to the wind.

Sharpness at 200mm

Here are the full images shot at 200mm, scaled down and sharpened. Click for larger images.


Lumix 45-200 @ 200mm f/5.6	Lumix 100-300 @ 200mm f/4.9

To better compare the sharpness, let's look at 100% crops. I have not applied any sharpening to these 1:1 images. These are taken from the image center. Click for larger images.

And from the top right corner:

Conclusion

Based on this study, it is quite clear that the Lumix G 100-300mm f/4-5.6 is the sharpest of the three lenses. It appears to be quite sharp even wide open. On the other hand, one could say that this is not surprising: It was used in the shorter end in this study, compared with the Lumix G 45-200mm f/4-5.6 which was used in the longer end of its zoom range. Also, the Lumix G 100-300mm lens has the lowest zoom ratio, which allows the designers to make less compromises.

The Lumix G HD 14-140mm f/4-5.8 disappoints a bit. But then again, it is a well known fact that it is not at its sharpest in the longer end, and 100mm is surely a long focal length for this lens.

The bokeh appears to be comparable between the 45-200mm lens and the 100-300mm lens. Perhaps one could say that the Lumix G 45-200mm is slightly more busy with the longer of these lenses, with some more "ringing" around the out of focus highlights. But they are pretty similar.

Lumix G 100-300mm f/4-5.6

2011-10-03T21:27:00.010+01:00

The Panasonic Lumix G 100-300mm f/4-5.6 Mega O.I.S. is a long tele zoom. This kind of lens would normally be used by people who are interested in photographing birds, wildlife, spectator sports, safaris, and so on.

More mature DSLR camera systems are, generally speaking, better suited for these applications. This is due to a better continuous autofocus, which is possible with the PDAF system used in DSLR cameras. Hence, people with these interests, are probably using Canon and Nikon cameras, rather than Micro Four Thirds. However, with the introduction of the Lumix G 100-300mm, M4/3 users have a possibility to check this out.

There is an alternative lens with a similar focal range as well, the Olympus M.Zuiko Digital ED 75-300mm f/4.8-6.7. The Olympus lens does not feature built in image stabilization, and is better suited for use on Olympus M4/3 cameras.

To see how this lens is different from the smaller tele zoom (Lumix G 45-200mm f/4-5.6) and the superzoom (Lumix G HD 14-140mm f/4-5.8), take a look at this diagram:

In this picture, we have the focal length as the x-axis, and the maximum aperture as the y-axis. What we see, is that the 100-300mm lens covers longer focal lengths, of course, but also that it achieves a larger maximum aperture where it overlaps with the other lenses. So using the 100-300mm lens gives you the possibility to get a faster shutter speed, and more selective focus than the other lenses, for longer focal lengths.

Build and ergonomics

At the time of writing, the Panasonic Lumix G 100-300mm f/4-5.6 Mega O.I.S. tele zoom lens is the largest Micro Four Thirds lens available. It is a long tele zoom, and as you can see from the comparison below, it is significantly larger that the smaller brother Lumix G 45-200mm f/4-5.6:

And the difference is even larger when the zoom is extended to the max:

The Lumix 100-300mm lens has a filter thread diameter of 67mm. This is larger than the Lumix G HD 14-140mm f/4-5.8, which measures 62mm. The diameter of the front lens element is also larger with the 100-300mm lens.

Both lenses are supplied with hoods, and I recommend using them. The pictures above show the lenses without the hoods.

The Lumix 100-300mm lens appears to have a good build quality. Just like most Panasonic lenses, it has a metal lens mount, and the rest of the construction is based on various plastic compounds. I think this is a sensible material to use for such a lens.

Gripping the front end of the lens reveals that it is slightly loose, also when the zoom is not extended. This is normal for zoom lenses.

The zoom ring is a bit stiff, especially from the middle to long end of the zoom range. This makes smooth zooming very difficult. From what I have read, the zoom ring is a bit stiff on new lenses, and becomes smoother with use. So this doesn't worry me much. The zoom ring is covered with a ribbed rubber-like cylinder, which is thick and allows for a good grip.

The lens is heavy, heavier than the Lumix G 45-200mm f/4-5.6 and Lumix G HD 14-140mm f/4-5.8 lenses. I am using the lens on the Panasonic GH2 camera, and find that they go well together. It is fairly easy to hold the camera and lens due to the generous grip on the camera. With smaller M4/3 cameras, I think you might find the operation more difficult. Especially with cameras like the GF2 and GF3, which do not have any significant grip.

The zoom ring is wide and has a rubbery substance which makes it well suited for holding. It is natural to hold the camera with the right hand, and hold the left hand around the zoom ring. I found that I often touched the focus ring accidentally, causing the camera to go into focus assist mode with a zoomed view. However, half pressing the shutter button brings the camera back to the ordinary view mode, so this is no problem.

Autofocus

Just like the other Panasonic zoom lenses, the autofocus is very fast and silent.

One disadvantage with the smaller brother, the Lumix G 45-200mm f/4-5.6, is that it loses focus when zooming. The Lumix G 100-300mm lens is advertised to have some technology that makes it easier to retain focus during zooming. So does it mean that the lens is parfocal, that the focus is maintained when zooming? It looks like it is more parfocal, at least.

Here is a video example which illustrates the autofocus while zooming. The clip was recorded while holding the camera without using a tripod or any support. The distance to the squirrel was about 2m, close to the minimum focus distance of 1.5m. I started with the lens in 100mm, and zoomed slowly in to 300mm. Then I zoomed back out to 100mm:

What we see here, is that the focus is not perfect while zooming. It is not until I stop zooming at 300mm that the focus is regained perfectly, and then it takes a couple of seconds. The same can be seen when zooming out.

Of course, one should normally be careful zooming while video recording, since it is very difficult to zoom smoothly. But this video shows that perfect focus while zooming cannot be expected. Again, however, it is much better than when using the Lumix G 45-200mm f/4-5.6 lens.

Image stabilization

I have not done any scientific studies, but to me it appears that the OIS is more efficient than the Lumix G 45-200mm f/4-5.6 lens, especially during video recording.

Here is an example video, recorded handheld at 300mm. I left autofocus on. In retrospect, it would probably have been better to focus once, and then turn AF off. You can see that the focus is cycled now and then during the video, which is a bit distracting:

Note that the helicopter rotor blades look bent in the video. This is due to the rolling shutter effect.

I'm sure that with some practice, it should be easy to make less shaky videos.

Bokeh

Bokeh is the nature of the rendering of out of focus areas. When leaving some parts of an image out of focus, the rendering of these parts is important: While the photographer usually means to point the attention towards the areas that are in focus, a distracting bokeh can fool the viewer to spend more time looking at the background. So a smooth bokeh is important in blurring the areas that are out of focus, and not causing distractions.

Here are a couple of real life examples. From Washington Square Park, 150mm, f/5.6, ISO 1250, 1/320 second exposure:

By enlarging a part of it, we can study the bokeh more closely:

Here we see that there is some ringing around the highlights. This is not ideal, as it is distracting. In this example, I would say that the bokeh is not perfect, but it is not overly bad either.

Another example, 218mm, f/5.1, ISO 320, 1/500 second exposure:

Looking more closely at the out of focus rendering, it looks pretty normal:

Flare

The lens comes with a hood, and I recommend using it. The hood gives some protection against stray light coming from outside of the image circle (at 100mm focal length), and should reduce some flare problem.

Even with the hood, the lens can be negatively affected by flare, if there is a strong light source in the image frame, or just outside.

Here is an example illustrating this. It was taken at nine o'clock in the morning from East 43rd street 7th Avenue. The sun is just behind the Chrysler Building, and causes the clouds to be very bright (100mm, f/5.6, ISO 160, 1/2000 second):

This is a difficult situation for any lens, and especially a long tele lens. However, I would say the lens handles the backlight pretty well. The contrast is probably reduced a bit, but not much. And there is no significant ghosting or other negative effects.

Let's see how it goes at 300mm (f/5.6, ISO 160, 1/4000 second):

In this case, it looks like there is more significant loss of contrast due to flare. This is not unexpected: Generally it appears that flare is a larger problem the longer the lens is.

To see how the same building looks without the flare, let's view it from the other side, without the backlight (at 100mm and 300mm):

100mm, f/4, ISO 160, 1/2500 second.

300mm, f/5.6, ISO 160, 1/1600 second.

By looking at the difference between these images, it is clear that flare causes a significant loss of contrast, especially at 300mm focal lenght. Of course, the exposure of the building wall is not entirely similar in the two situations: In the backlit photos, the building is less exposed.

Sharpness

Enlarging the images of the Chrysler Building above makes it possible to do a quick assessment of the sharpness of the lens. This is from the image at 100mm, unsharpened (click for larger version):

And at 300mm, also unsharpened (click for larger version):

In these examples, I think the sharpness appears to be quite good, especially considering that they are taken at maximum aperture.

In this comparison, I show that the Lumix G 100-300mm lens is sharper than the Lumix G 45-200mm and Lumix G HD 14-140mm lenses.

Example images

Here are a couple of example images.

From Bronx Zoo, 223mm, f/5.1, ISO 250, 1/500 second:

From Williamsburg, 258mm, f/5.4, ISO 640, 1/125 second:

Both these images could benefit from being cropped a bit, but I show them here as the were taken.

Conclusion

This lens appears to tick all the boxes: It focuses quickly, it has effective OIS, it appears to be sharp and has good bokeh. And the price is not unreasonable.

So should you buy it? If you only want one tele zoom lens, then you should rather get the smaller brother, the Lumix G 45-200mm f/4-5.6 lens. Because it is smaller, lighter, cheaper, and most importantly, because it covers a focal length range that you are more likely to need on a daily basis.

The Lumix G 100-300mm lens, on the other hand, is a very long tele lens. Even in the short range of the zoom range, it already has a very narrow field of view. So it is a lens you would bring to special events, like sports, safari, and so on. It is not a lens you would normally leave on the camera while you walk around.

If you need a long tele lens, there are not really any alternatives to this lens. It's good then, that the Lumix G 100-300mm lens gives good image quality, at a reasonable price.

Lens buyer's guide

2011-09-20T22:10:00.004+01:00

So, you have a Micro Four Thirds camera? Now, what lenses should you buy?

Before trying to answer this question, let's take a step back and ask: Why would you need more lenses?

Compact cameras and interchangeable lens cameras

A user coming from the compact camera world may be confused by the apparent need for more lenses. Even fairly inexpensive compact cameras comprise a feature packed lens: A zoom range of 12x or more, starting at a very wide angle, macro functionality, and even pretty decent maximum aperture (a low f-value). All this in a small package.

When "upgrading" to a Micro Four Thirds camera with the kit lens, they may easily be disappointed. They now have a larger, more expensive camera, which only features a 3x zoom lens, starting at 28mm equivalent wide angle, and no macro functionality. How is this an upgrade at all?

The answer to this lies in the size of the imaging sensor. Compact cameras generally have a very small sensor, which allows the manufacturer to design very small lenses that have all the functionality most people would want. With a larger sensor, it is physically impossible to design a lens which does the same, at least within reasonable economical constraints.

So why don't all cameras have small sensors, so that the built-in lens can solve all the photographic needs of the user?

It turns out that a camera with a larger sensor has other advantages. The main four advantages for a larger sensor camera, as I see them, are:

1. Ergonomics. A larger sensor camera needs to be larger, and hence the camera itself has more space for buttons, wheels and levers. This gives the user a better grip to hold, and easier access to functions through the user interface. Compact cameras only have room for a small handfull of buttons, and require the user to use menus to access the camera functions.

2. Sensitivity. With a larger sensor, each photosite has a larger physical area, meaning that you can theoretically get a better image quality with in a low light situation (high ISO). This can also give a better dynamic range, and overall better image quality.

3. Selective focus and bokeh. With a small lens camera, the depth of focus is very wide, meaning that a lot of the image will be in focus. While this is good for a lot of applications, larger sensor cameras allow for selective focus, making the background of the image go out of focus.

4. Diffraction. A physical concept called diffraction dictates that there is a limit to how high the pixel density on the sensor can be. Hence, to get more megapixels, the sensor needs to be physically larger.

However, the disadvantage with a large sensor camera is that not one single lens will cover all the photographic needs. Hence, the camera is often designed to have interchangeable lenses, so you can change lens depending on what kind of image you intend to take.

Micro Four Thirds Lenses

The main players in the Micro Four Thirds camera system are Olympus and Panasonic. Since all cameras and lenses are from the same system, they can be combined. So you can put an Olympus lens on a Panasonic camera, and vice versa. In some cases, however, it makes sense to match the manufacturer when buying lenses. I will comment this later in the article.

In this article, I have split the content into a number of lens categories. Before going into the details, here is a brief description of each category:

Pancake Lenses: This is not a common lens category. For example, for the Nikon lens system, existing for more than fifty years, there is only one single lens which is generally regarded as a pancake lens. Pentax has a handful of pancake lenses. But for the Micro Four Thirds lens system, size is important, which may be why pancake lenses are more common here.

Low Light Lenses: For use in low light environment, for example when you want to photography people indoor without using a flash, for concert photography, and so on.

Kit Zoom Lenses: When you buy a camera, you often have the option to buy a basic zoom lens in a kit together with the camera. This lens is generally small, light, cheap, and often has a zoom range of around 3x. It is not too common to buy this type of lens standalone.

Tele Lenses: Long focal length tele lenses are used to photograph things that are far away.

Wide Angle Lenses: Covering a very wide field of view, these lenses allow you to pack a lot of features into one single image. However, the wide perspective can give unexpected perspective distortions.

Superzoom Lenses: These lenses are designed for covering a wide range of focal lengths, from wide angle to tele. Hence, having one of these lenses on your camera should remove the need to change lens often. The zoom range of these lenses is usually 10x or more.

Portrait Lenses: For taking portrait pictures, meaning a headshot, or a head-and-shoulders picture, usually at about 1-2 meters distance.

Specialty Lenses: Other lenses that don't belong in other categories.

Here are my opinions about the lenses in these categories:

Pancake Lenses

The lenses in this category are prime lenses, meaning that they are not zoom. They have a constant focal length, and hence, a constant field of view.

There are three choices: Panasonic Lumix G 14mm f/2.5, Olympus M.Zuiko 17mm f/2.8, and Panasonic Lumix G 20mm f/1.7 (from left to right below, not to scale).

These lenses are somewhat different. The Lumix 14mm lens is the widest, obviously, and also the smallest and lightest.

The Lumix 20mm lens is the fastest, it has the largest maximum aperture. This makes it the most useful for low light photography. Also, with the longest focal length, it is more useful for photographing a person, but not so good for a group of persons. On the other hand, it has a fairly slow and noisy autofocus.

Here is my article which compares the 14mm and 20mm lenses from Panasonic.

The Olympus 17mm lens doesn't stand out too much. It is not the smallest, nor the widest or fastest of the pancakes. On the other hand, it is the cheapest. The field of view lies between the two Panasonic pancake lenses.

Do you need to match the manufacturer when buying the pancake lenses? Not really. If you put a Panasonic lens on an Olympus camera, you don't get automatic software correction of some chromatic abberation artifacts. But the lenses don't exhibit too much of these artifacts anyway, so this is no big problem.

So what lens should you buy? If autofocus (AF) during video is important, don't choose the Lumix G 20mm f/1.7 lens. It has too slow AF, and can easily lose the focus for several seconds during video recording, especially in low light.

If low light performance is important, of course you should choose the one with the largest maximum aperture, which is the Panasonic Lumix G 20mm f/1.7.

None of these lenses can be considered portrait lens: They are too short for that. However, they can all be used for environmental portraits, in which you include more of the person than just the head and shoulders. For pictures of a group of people, one would normally choose the widest, the Panasonic Lumix G 14mm f/2.5.

All these lenses are considered to be good optically, however, people often say that the Olympus 17mm f/2.8 is slightly inferior to the Panasonic Lumix pancake lenses.

Low Light Lenses

A low light lens is a lens designed for being used in situation where the available light is low, and you don't want to use a flash. This could be indoor, at a concert, outdoor at night, and so on.

The lenses in this category have a large maximum aperture, and hence, a low f-number. The Panasonic Lumix G 20mm f/1.7 from the pancake category is also a low light lens. With an aperture of f/1.7, it is among the fastest Micro Four Thirds lenses available.

At the moment, the ultimate low light lens is the Panasonic Leica DG Summilux 25mm f/1.4. Corresponding to a classic normal lens for a film based SLR system, 50mm f/1.4, this lens is good photographing in low light environments, and when you want a high degree of selective focus and bokeh. Sporting a Leica logo, it is a rather expensive lens:

25mm is perhaps not the optimal focal length for a low light lens. It is too short for a portrait lens, and too long for photographing a group of people indoor. But, it remains a classic focal length for bright lenses, and I am sure many people like this lens a lot.

There is also another low light lens available at a rather reasonable cost: The Olympus M.Zuiko Digital 45mm f/1.8. (See the Portrait Lens section below for more discussion.) On a Panasonic body, you will have no image stabilization, which may be a problem with this fairly long focal length. You cannot expect to video record stably without some support.

Kit Zoom Lenses

Kit zoom lenses are usually bought together with the camera. So to include them in this guide might seem a bit superfluous. However, for the sake of completeness, here are my opinions on them.

In this category, it is wise to pair lens and camera according to the brand. This is because Panasonic and Olympus have chosen different philosophies when it comes to Image Stabilization.

Panasonic

Three lenses are available with the Panasonic brand: Lumix G 14-45mm f/3.5-5.6, Lumix G 14-42mm f/3.5-5.6, and Lumix X PZ 14-42mm f/3.5-5.6, all with OIS built in. Shown below, from left to right:

The lenses above are also sorted according to date of launch: the 14-45mm lens was the very first kit zoom lens, sold with the Panasonic Lumix G1 camera. It was later replaced with the newer kit zoom, the 14-42mm (middle, above). Finally, in 2011, the pancake kit zoom with powerzoom, Lumix X PZ 14-42mm was launched.

So what lens should you choose? The first kit zoom, the 14-45mm, is probably the better than the second, the 14-42mm. The second version was made mostly to cut costs, and features a 25% smaller front lens element. It is also lighter, partially due to the plastic lens mount.

Personally, I think you shouldn't spend the extra effort to get the now discontinued, older, 14-45mm lens. While it is probably better than the second, the 14-42mm is perfectly fine, in my opinion. You should rather spend the effort to take pictures, and save the money for future lens purchases.

The third kit lens announced, the Lumix X PZ 14-42mm f/3.5-5.6, is completely different. It is made to achieve two extra goals: To be very compact, and to feature a power zoom. It extends using an internal motor before being usable upon powerup. Zooming can only be done with the zoom lever on the lens side, which engages a dedicated internal zoom motor.

Motorized zoom is largely a nuisance when photographing. You have much better control using a zoom ring. However, if you intend to zoom during video recording, a power zoom is needed. It is virtually impossible to zoom smoothly using your hand. Many would say that zooming during video should be avoided, as it seldom looks good anyway. But with a motor zoom, you have a much better chance of pulling it off.

It doesn't even have a focus ring. To focus, you must use a focus lever on the side. This, combined with the lack of a zoom ring, makes the lens somewhat awkward for still image photography. So if you're only interested in still images, this lens is not ideal for you. Unless, of course, you also value compactness.

Olympus

Olympus also offers three kit lenses: Olympus M.Zuiko Digital ED 14-42mm f/3.5-5.6, Olympus M.Zuiko Digital ED 14-42mm f/3.5-5.6 II, and Olympus M.Zuiko Digital ED 14-42mm F3.5-5.6 II R (left to right below):

With the Olympus kit lens, the choice is simple: Get the newest one. The II-version is better optically than the original kit lens. And the II R-version is largely the same lens, but focuses better, especially during video.

Tele Lenses

Tele lenses are designed to photograph items that are further away. The zoom range generally starts at the portrait lens focal length, corresponding to around 40-45mm for the Four Thirds format. Since they usually feature an aperture of f/4 at this focal length, better than the kit zooms, they can be used as portrait lenses if you mind the background a bit.

Other uses for tele lenses are spectator sports, wildlife, and other situations where you cannot get closer to what you are photographing.

With the narrow field of view of tele lenses, image stabilization is important, and it makes sense to match the manufacturer of the camera and lens.

Panasonic

The Lumix G 45-200mm f/4-5.6 is the most reasonably priced tele lens for Panasonic cameras, and in my opinion, it gives a good value for money. It features quick and silent AF, and good sharpness. In the longer end, around 150-200mm, the sharpness is not as good, but still usable.

For Panasonic camera users who want a tele lens, I would recommend the Lumix G 45-200mm f/4-5.6 lens. The only exception is if you know that you need a very long lens, in which case it may make more sense to buy the bigger brother, the Lumix G 100-300mm f/4-5.6:

While the smaller lens starts at the typical portrait lens focal length, 45mm, the larger starts at 100mm. 100mm is already a very long lens for the Four Thirds format. So as the 45-200mm lens can be used as a "walk around lens", the 100-300mm lens remains a specialized long tele lens at all zoom configurations, with a more limited area of use.

Just like in the kit zoom category, Panasonic has a new power zoom lens, the Lumix X PZ 45-175mm f/4-5.6:

It is more compact and lighter than the Lumix G 45-200mm tele zoom lens. Also, it does not extend when zooming, meaning that it is a more solid construction. There is no wobbling front segment. It's main feature is the power zoom, which works very well. It can be operated by a lever, or by a "zoom by wire" electronically coupled zoom ring.

In my test, it has better optical properties than the older Lumix G 45-200mm lens.

Olympus

Olympus have got two tele lenses, with one covering longer focal lengths. Again, get the shorter lens, the Olympus M.Zuiko Digital ED 40-150mm f/4-5.6 for most tele needs. There is also a newer version with better autofocus performance, the Olympus M.Zuiko Digital ED 40-150mm f/4-5.6 R. As the optical formula is similar, get the newest version (right, below), if you have the possibility:

The longer lens, the Olympus M.Zuiko Digital ED 75-300mm f/4.8-6.7, is built to be compact, and for that reason features a smaller maximum aperture than the similar lens from Panasonic. This makes it somewhat less suitable for applications where you need to capture movement with a fast shutter speed, e.g., sports, or where the light is limited.

This is a lens for those who value compactness of their system, and are willing to pay for it.

Wide Angle Lenses

To capture a wide cityscape, or a group of people at a short distance, you need a wide lens. There are some quite wide lenses available for the system. As image stabilization is not as needed for short focal lengths, I'd say you can put these lenses on both Panasonic and Olympus bodies. Don't worry about the lack of image stabilization on Panasonic bodies, is my opinion.

The (relatively) low cost alternative at the moment is the Olympus M.Zuiko Digital 9-18mm f/4-5.6:

It has a reasonably small size, low weight, and performs well. The focal length range is useful: Going from a pretty extreme wide angle to a "normal" field of view in the long end.

For the person who wants even more extreme wide angle performance, the Panasonic Lumix G 7-14mm f/4 is the right choice. It will set you back more in terms of cost, but offers a staggering wide angle view in the short end. It performs very well optically, and is built to a high quality.

The Olympus M.Zuiko Digital 12mm f/2 is a prime wide angle lens. At 12mm, it is not extremely wide, but should be wide enough for many applications. It has a construction involving a lot of nicely polished metal, and is quite unusual for having a focus scale, and a depth of field scale:

It is a pricey lens, and you probably pay some premium for the retro metal construction.

Superzoom Lenses

Superzoom lenses mimic the "compact camera feeling", in that they enable a very large zoom range. Starting at 28mm film equivalent wide angle, and with a zoom ratio of 10x or more, they cover the focal length people tend to use most. The downside is that the lenses are large, expensive, and don't have very impressive maximum aperture.

As image stabilization is important in the longer focal length range of these lenses, it is recommended that you buy the Panasonic lens for use on a Panasonic camera, and the Olympus lens for an Olympus camera.

The Panasonic Lumix G HD 14-140mm f/4-5.8 is a large, heavy and expensive lens. It sports the "HD" designation, indicating fast and silent autofocus, and a near stepless aperture. It is quite sharp, expect in the very widest zoom setting, and in the longest focal range. This is usual for superzoom lenses.

Should you buy this lens, rather than the Lumix G 14-42mm f/3.5-5.6 and the Lumix G 45-200mm f/4-5.6, which when combined cover a larger focal length range at a smaller price? That depends. Combining two lenses may mean that you miss the occasional shot: Changing between the lenses takes some time, while just rotating the zoom ring of the superzoom lens is very quick.

The Olympus M.Zuiko Digital ED 14-150mm f/4-5.6 features a slightly longer zoom range. However, that is just barely significant. What is more significant, is the relatively smaller size and weight. The Olympus superzoom lens is much more portable:

Both lenses are pretty comparable when it comes to optical performance, according to what I have read.

Portrait Lenses

According to the traditional understanding of the word, a portrait lens is a lens with a focal length of around 42-52mm (on a Four Thirds size sensor), with a fast maximum aperture. At the moment, there is only one single lens in the Micro Four Thirds lineup which satisfies this, the Olympus M.Zuiko Digital 45mm f/1.8:

This lens is priced at a fairly reasonable level, which makes it a must have for Micro Four Thirds users who are serious about portrait photography.

With no Optical Image Stabilization built in, it is not too good for handheld video recording, neither with an Olympus camera, nor with a Panasonic camera.

Some would say that a portrait lens must have a very fast aperture, preferably f/1.4 or better. They might be dissatisfied with the f/1.8 maximum aperture of the 45mm Olympus lens. I would personally say that f/1.8 is large enough to get a sufficiently thin depth of focus (DOF) for portrait photography.

The Panasonic Leica 45mm f/2.8 1:1 macro lens could also be used as a portrait lens, in my opinion, even if the maximum aperture is much smaller than the traditional definition of a portrait lens dictates. As long as you make sure the background is not too distracting, you should be fine using this lens as a portrait lens, in my opinion. (See the Specialty Lenses category below.)

For a low cost alternative, you could also consider using the Lumix G 45-200mm f/4-5.6 tele zoom lens in the shorter end as a portrait lens. Or use the Olympus M.Zuiko 40-150mm f/4-5.6 if you have an Olympus camera body. With a maximum aperture of f/4 in the short end, you cannot blur the background as much as you might prefer. But with some planning of the composition, I don't see why you shouldn't be able to pull it off.

Specialty Lenses

If you are interested in macro photography there is one lens available at the moment, the Panasonic Leica 45mm f/2.8 1:1 macro lens. With a macro reproduction rate of 1:1, you can photograph items down to a size of 17mm x 13mm:

In my opinion, it can also double as a portrait lens, even though the aperture could have been larger for this application.

It focuses somewhat slowly, and for that reason is not ideal for video recording with AF. The optical image stabilization is not so useful for macro applications. It is a pricey lens, but the optical performance is good.

The lens with the very widest field of view is the Lumix G 8mm f/3.5 Fisheye lens. It focuses very quickly, and has a very short minimum focus distance, which can be used for some interesting effects.

Due to the fisheye perspective, it has a somewhat limited usefulness, and could be viewed as a novelty lens by some.

Panasonic has launched a 3D lens. It features two fixed focus, fixed aperture lenses at 12.5mm f/12:

But don't think that this is a wide angle lens, with the 12.5mm focal length. As the lenses project much smaller image circles, there is an additional crop factor of 2.6, giving a 65mm field of view, relative to a 135 film camera standard. Since the two images projected are small, the resolution of the images are limited.

This lens only works on fairly recent Panasonic camera bodies. And, contrary to what most people would expect, it cannot be used to record 3D videos.

The 3D stereo base is small, only about 10mm. So the 3D effect is only significant for fairly close macro images. Photographing objects that are further away yields a limited stereo effect. So the usefulness of this lens is not very high.

Conclusion

The Micro Four Thirds lens lineup has become quite good. People with a camera and a basic kit lens most likely want to achieve something new with their lens purchase. Here are some common needs, as I see it:

For a more compact lens, look at the pancake lenses. The Panasonic Lumix G 20mm f/1.7 combines a small size with a good low light performance, and for that reason has become an instant classic. The Panasonic Lumix G 14mm f/2.5 has a very impressive small size, and is good for wide angle and fast AF.

For extending the tele effect of the kit zoom, complement it with the Lumix G 45-200mm f/4-5.6 (for Panasonic cameras), or the Olympus M.Zuiko Digital 40-150mm f/4-5.6 (on an Olympus camera, get the newer R-version if possible.) You could also consider the newer powerzoom Panasonic Lumix X PZ 45-175mm f/4-5.6, especially if you are into video, or if compactness and lightness is important for you. For birding or safari use, the Lumix G 100-300mm f/4-5.6 is pretty much the only choice at the moment.

For a one lens does it all superzoom, get the Panasonic Lumix G HD 14-140mm f/4-5.8 for use on a Panasonic camera, or the Olympus M.Zuiko 14-150mm f/4-5.6 for use on an Olympus camera.

In the wide angle category, the Olympus M.Zuiko Digital 9-18mm f/4-5.6 gives a good value for money.

If you are interested in portraits, the Olympus M.Zuiko Digital 45mm f/1.8 appears to be a good choice, for a reasonable price.

If you want the luxury feel, and let me say that there is nothing wrong with that, consider the Olympus M.Zuiko Digital 12mm f/2 wide angle lens with a retro metal construction, the Panasonic Leica 45mm f/2.8 1:1 macro lens, or the Panasonic Leica 25mm f/1.4. The metal construction of the Olympus lens, and the premium Leica branding of the Panasonic lenses contribute to a higher price level, but you surely get a good lens in return.

(The images in this article have been picked from four-thirds.org.)

Noise comparison, aperture change

2011-09-08T20:53:00.001+01:00

I have previously compared the focus noise of various lenses. The conclusions from my analysis were hardly surprising, for example, the Lumix G 20mm f/1.7 pancake lens had a rather loud focus noise, due to the traditional focus assembly which moves all the lens groups back and forth.

The lenses with an internal focus mechanism generally featured lower noise, with the Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 Macro and Lumix G HD 14-140mm f/4-5.8 as exceptions. In the latter case, I believe the microphone was too close to the lens, giving biased results.

You could ask why worry about the aperture change noise. After all, the aperture is generally stopped down just before the shutter is released. And for all Micro Four Thirds cameras, the shutter noise is rather high. So the aperture noise is simply drowned by the shutter noise anyway.

However, there are times when you don't trigger the shutter. This could be when using the new high speed, low resolution mode of the Panasonic GH2. Or, quite simply, when recording videos.

Also, some time in the future, we are going to get cameras without mechanical shutters. When the global shutter technology is mature enough, we will see this in Micro Four Thirds cameras. Then, the only noise we will hear is the focus noise and aperture noise.

To measure the aperture change noise, I placed a mobile phone near the camera, running the "Decibel Ultra" app, to measure the noise level. While I don't trust the absolute measurement of the phone, I think it is good enough to look at the relative levels of noise.

The GH2, and many other Micro Four Thirds cameras, has the feature of stopping down the aperture to preview the depth of focus (DOF). This is very useful, especially for macro photography. I use this feature to toggle the aperture between maximum and f/7.1.

The test

Results

I have only noted down the peak decibel measurements. The results:

Lens	Measurements	Average
Lumix G 8mm fisheye	77 76 77	77 dB
Lumix G 14mm	79 77	78 dB
Lumix G 20mm	76 75 73 76	75 dB
Leica Lumix DG 45mm macro	80 82 81 83	82 dB
Lumix G 45-200	83 80 81 84 83	82 dB
Lumix G 14-42	75 76 75 75	75 dB
Lumix G HD 14-140	78 78 81	79 dB

Conclusions

According to the marketing material, the HD designation of the Lumix G HD 14-140mm f/4-5.8 superzoom lens means that it should have fast autofocus, low noise autofocus, and near stepless low noise aperture.

After my analysis of the AF speed, the AF noise and now, the aperture noise, I cannot see that the lens is that special. It performs pretty much like the basic kit lens. What I haven't looked at, though is the aperture change, which is quoted as "near stepless". Accurate to 1/6 stop, is what I have seen quoted.

That said, the Lumix G HD 14-140mm f/4-5.8 zoom lens does have a softer sound when changing aperture.

In terms of aperture noise, the lenses appear to perform quite similar. And this is not strange: The aperture diaphragm mechanisms are probably rather similar between the lenses.

Interesting macro images with a fisheye lens

2011-08-25T18:37:00.004+01:00

If you want a very wide lens for the Micro Four Thirds system, there are two choices: The Panasonic Lumix G 7-14mm f/4 and the Olympus M.Zuiko 9-18mm f/4-5.6. The Panasonic lens is the widest, and is also the most expensive. Both are considered to be quite good.

But it's easy to forget that there is a third choice, the Panasonic Lumic G 8mm f/3.5 fisheye lens.

When considering which of these wide lenses to buy, I landed on the unconventional choice: The fisheye lens. My reasoning was that it has the widest field of view, and is the most compact. The compactness can be illustrated by this picture:

But I was also fascinated by the very short minimum focus distance. In the specifications, this close focus distance is stated as 0.10m. This doesn't sound very impressive. But keep in mind that the focus distance is measured from the sensor plane. So the distance from the front of the lens is only about a couple of cm, or about one inch.

This close focus distance opens up a number of creative possibilities. Below is one example. I put a LEGO figure very close to the lens. It is actually slightly closer than the minimum focus distance. But to keep it reasonably in focus still, I set a very small aperture, f/18. And I used manual focus to make sure the focus was as close as possible.

The resulting image, when cropped a bit, is this:

I think the distorted perspective due to the very wide field of view makes the image interesting.

A big drawback with this method is that the lens casts shadow on the subject. It is very difficult to achieve a proper lightning, as the field of view is very wide. Putting a light source close, so that it illuminates the clown's face, will usually make the light source visible in the picture. Which is not the intention, clearly.

Let's see what we can do when taking the lens outdoors. Here is a picture of a butterfly:

Unlike the clown picture, this image is completely uncropped. It was taken in the same way, by setting the focus as close as possible, and using a small aperture, f/11, for a very deep depth of field. I used ISO 250 and 1/60 second shutter speed.

To take the picture, I put the front of the lens about 2cm from the butterfly. Of course, this made it rather stressed, and it left the scene shortly after. So the time I had to compose the image was very short.

Looking at the composition, it is clear that it leaves quite a bit to be desired. For example, the butterfly is squarely in the middle of the image, which is usually a bit boring. It is common to put interesting objects about 1/3 from the frame edges, to make the image more exciting. This is usually referred to as the rule of thirds. Some Panasonic cameras can be configured to show the guidelines that correspond to the rule of thirds in the display, to aid in the composition. Here is an example from the Panasonic GH1:

The Panasonic GH1 display, configured to show the rule of thirds guidelines in white. Placing interesting items where these lines meet usually gives an interesting composition. It is common to place the horizon along one of these lines.

Also, it would be fine if the flower shape was repeated more times in the frame. We can see one uncluttered flower in the right part of the image, but two more would be fine.

Finally the background could be more interesting. Let's say we had a couple walking down the path behind the butterfly. That would surely make the image a lot better.

But planning all this is very difficult, since the butterfly will leave the scene after a split second when putting the camera in it's face, literally. I still think this image illustrates well the creative potential of the lens.

Looking at how a typical macro image of a butterfly looks like, let's consider this one taken with the Panasonic Leica 45mm f/2.8 1:1 macro lens:

This is what a macro picture usually looks like. Even though it was taken with a small aperture, f/7.1, the depth of field is still very thin. So the background is completely out of focus. The other exposure details are: ISO 100, 1/100 second.

The thin depth of focus is an advantage: It means that you don't need to worry about the composition of the background. The background will be blurred out. As long as the bokeh is pleasing, you can put your energy into keeping the subject interesting.

But it can also be a disadvantage. The background could potentially be used to make the image more interesting. Putting an insect into an environment, rather than just picturing it with the background blurred out, can make a very stunning photo.

But a macro lens will virtually always keep the background out of focus, even with a very small aperture. This is due to the relatively long focal length. The macro lens used in the picture above has a focal length of 45mm, which is pretty common for such a lens.

The fisheye lens, on the other hand, has a very short focal length, only 8mm. This gives a deeper depth of focus (DOF), and keeps the background more in focus.

The conclusion here is that the fisheye lens can be used to make very interesting close up images. But as the background is more in focus compared to when using a macro lens, the composition can be very tricky.

"Dances with fire", example Lumix 14mm video

2011-08-14T15:26:00.006+01:00

This video was recorded using the Panasonic GH2 and the Lumix G 14mm f/2.5 pancake lens.

I left everything on auto, and just pushed the red video button. This gives me a 720p AVCHD video stream. Since I dislike the highest resolution 1080i mode, due to the interlace, I tend to use 720p progressive mode. I have the European version of the camera, so the frame rate is 50fps.

Sadly, the camera does not seem to record the image parameters when making video captures. So I don't know for sure what aperture, shutter speed and ISO was used. But I would guess the camera selected the largest aperture, f/2.5. And the shutter speed was probably as slow as possible for a 50 fps video, so around 1/60 second. The ISO was probably pushed up quite a lot, I would guess around 1600-3200.

Focus

I had autofocus selected (AFS). It would probably have been a good idea here to prefocus, and then select manual focus (MF) during the video capture. That is to avoid having the focus hunt during the video capture. You can see that the camera jogs the focus back and forth now and then, to verify that the image is in focus. But since the Lumix G 14mm lens focuses very fast, this is barely noticeable, even in this low light situation.

With the Lumix G 20mm f/1.7 pancake, the focus is slower, and it can wander off for some seconds when recording a video. For the 20mm lens, it is best to have some control over the focus during videos.

White Balance

The white balance was also left on auto (AWB). This gives a slightly yellow tint to the images. Perhaps I could have tweaked the white balance better. But this is hard to do when you don't have time to plan the video capture in advance. On the other hand, the yellow colours are actually true to the actual lightning conditions.

Flare

Notice that there is some flare in the video. You can see that the flames generate greenish ghosting symmetrically opposite along the optical axis. This is quite common when you have strong light sources inside the image frame.

This illustration shows the relationship between the actual light source and the flare:

A lens hood would not have helped, since the hood is only designed to keep out light which comes from outside the image frame.

Generally, flare is more of a problem the more lens elements the lens is composed out of. So generally, you would find flare to be a bigger problem for a zoom lens, which can easily have more than ten individual lens elements, than for a prime lens. The Lumix G 14mm f/2.5 pancake lens only has six lens elements. However, the optical formula and the quality of the lens elements is also important for the flare characteristics.

Using a protective lens filter on the front of the lens can give you more lens problems, especially for low quality lens filters.

Audio

I used the onboard microphone, and left the levels on auto. It sounds like the sound is clipped some times. But I would guess this is actually due to the sound system being run to loud, and not due to the microphone.

Using an external microphone probably has the potential to give better sound in the video recording. But it makes the setup look much more professional, which might scare some people, and hence negatively affect the video. Using the GH2 with the 14mm pancake lens gives a very compact and non-obtrusive package, which is handy for recording everyday life.

Lumix 14mm as a video lens.

The very fast autofocus and the inaudible focus action make the Lumix G 14mm f/2.5 an ideal video lens.

It has a generously wide field of view, which is useful when video recording a group of people. The wide field of view also makes it easy to handhold the camera without the hand shake affecting the video stream too much.

The small size and unobtrusive looks also makes it easy to get close to people without scaring them, which is a big plus if you intend to video record people.

On the other hand, a zoom also comes handy for video use. For some more flexibility, I would recommend the Lumix G 14-42mm f/3.5-5.6 basic kit zoom. It is light, very fast focusing, and pretty good quality.

A tale of a broken Lumix kit lens

2011-08-08T19:45:00.002+01:00

Contrary to much of the online opinion, I think that the basic kit lens from Panasonic, the Lumix G 14-42mm f/3.5-5.6, is rather good. Considering the price, the size and the weight, I think it gives a good performance. The autofocus is fast, the sharpness is generally good.

However, when evaluating the bokeh characteristics of the lens, I noticed that the out of focus highlights were non-round. This is found for some lenses, for example the Lumix Leica 45mm f/2.8 1:1 macro lens has elliptical out of focus highlight rendering outside of the centre of the frame. But I found that the Lumix G 14-42mm lens had more like potato shaped highlights.

A closer examination revealed that the aperture diaphragm was indeed misaligned, giving non-round out of focus highlights for all stopped down aperture sizes. If found this to be so bad, that I took the lens back to the shop where I bought it in the first place.

The store keeper has some problem verifying that his off the shelf lens did not exhibit the same non-round aperture. I helped him by taking a photo with the lens mounted to the Panasonic GF2 camera at f/9, 2 seconds, and removed the lens during the exposure. Looking towards the light through the lens showed that his copy had a round aperture.

So he accepted my lens as defective, and sent it for repair.

After one month, I started enquiring about the lens. I always got the same answer: "The lens is just around the corner, should be in our store the beginning of the next week."

It was not until after three months that the lens finally did arrive in the store. When I went to pick it up, I was told that they simply replaced the lens with a new one. Why let me wait for three months when they would just give me a new copy?

Coming home, I once again checked if the aperture was rounded. See for yourself, this image was taken with the Lumix Leica 45mm f/2.8 1:1 macro lens:

In fact, my new lens exhibits exactly the same problem as the one I returned in the first place. I did check that the new lens has a different serial number, so it is not the same lens that I returned.

Letting me wait three months for a new lens is bad. But giving me a new lens which has the same problem as the one I returned is simply appalling.

Epilogue

I took the lens back to the retailer again. This time, they offered to change my lens directly from their stock. We tested two lenses, and neither had completely round apertures. One was as bad as my own lens, and the other was pretty rounded. So I took the best one.

I don't expect perfectness from a lens this cheap. So I am happy with the near round aperture opening.

Bokeh, part 1

2011-08-07T17:56:00.002+01:00

The term "bokeh" is commonly found when reading about photography. I would like to discuss bokeh in this series of articles. I don't intend to cover all aspects of bokeh, and I realize that not all would agree with my opinions. So you should view this as my personal opinions, and not as facts.

When using the word "bokeh", one normally means the nature of out-of-focus rendering. How the lens renders objects that are out of focus, the bokeh, depends on a number of factors, for example, the lens itself, the objects photographed, and settings like the focus distance and the aperture.

It does not make sense to say that "a lens has bokeh", or that "there is bokeh in a photograph". Rather, the term can be used to describe the out of focus rendering, e.g., "this lens gives me good bokeh", or "in this photo, the bokeh is distracting".

Focus

First of all, note that the term bokeh is only used about the parts of an image which is out of focus. So the first thing we must discuss is simply focus.

It might sound counterintuitive that we talk so much about objects that are out of focus. Isn't photography about taking pictures of things that are in focus? Who would want to keep anything out of focus in the first place?

We shall see examples where having some parts of the image out of focus makes sense, and hence, that the bokeh, the rendering of out-of-focus areas, is important. The first example below is taken with the Panasonic Leica 45mm f/2.8 macro lens:

f/2.8

f/22

In this example, we see that in the first image, taken with a large aperture, the foreground is in focus, and the background is out of focus. The second image is taken with a small aperture, a large f-number, leaving the background more in focus. I think most would agree that the first image is the best, because the background is less distracting.

For the image taken with the large aperture f/2.8, I would say that the bokeh is smooth. By this, I mean that the background which is out of focus is rendered in a way which blurs it effectively, and does not cause any distraction.

This is commonly called selective focus. By using a large aperture, we can choose what should be in focus and what should be out of focus. In fact, this is one of the advantages of using a camera system with a reasonably large sensor.

A compact camera has other advantages, for example size, and that you don't need many accessories. Take the Panasonic Lumix TZ-series, for example. It has a generous zoom, going from very wide angle to long tele, and also a macro function. All in a very small package. But since the sensor is small, it cannot do selective focus as in the example above. A small sensor gives a large depth of focus, which is good for some applications, but makes it more difficult to blur the background.

In the second image, I used the smallest possible aperture, f/22. Generally, one should be careful with using so small apertures, due to diffraction.

Setting the focus is one of the important parts of taking a photo. It is usually the first thing you would do when composing an image. However, with modern cameras, this is almost always set automatically, through autofocus. Further, many modern lenses don't have any focus scales. So the concept of focus might seem more abstract to people who have not used manual focus camera systems.

In the image above, the focus distance is illustrated as the distance from the camera, more specifically from the sensor plane, to the object where the focus is placed. When taking a picture of a person, it is normal to focus on the eyes of the subject. Many Four Thirds Cameras have face detection, and automatically choose to focus on the eyes when photographing people.

Having set the focus distance, anything in the focus plane is in focus, while items closer or further away are out-of-focus. The focus plane is defined as the plane normal to the lens axis, at the focus distance.

However, focus is not a binary concept. An item is not either in focus or out of focus. So what I wrote in the paragraph above is not true: Any item outside of the focus plane is not simply out of focus. It can be in focus to various degrees, depending on a number of parameters.

Another mistake above is that not all lenses feature a focus plane. With some lenses, the plane of focus is curved, e.g., spherical. A curved focus plane makes sense for portrait lenses. With a portrait lens, you would normally focus on the eyes of the subject, while keeping the eyes in the center of the image, and then reframe the image. However, with face detection and multiple focus areas, there is not a big need for a curved focus plane anymore.

Aperture

After setting the focus distance, the most common way to control what's in focus and what's not, is the aperture. A large aperture, e.g., f/1.4, will give a relatively shallow depth of focus (or depth of field, DOF), meaning that only points that are some short distance from the focus plane are in focus. On the other hand, a small aperture, denoted by a large f-number, makes more of the image in focus. This can be illustrated like this, using our previous example:

In this example, the left figure is holding the camera, and focusing on the eyes of the figure to the right. Using an aperture of f/5.6, the depth of field (DOF) covers the figure (green area), but not much of the foreground or background. Using a smaller aperture, f/11, the DOF now covers parts of the foreground and background as well (blue area).

This illustration is just an example, and not to be used in any real life application.

Older manual focus lenses typically include a focus scale with a depth of field indication. Here is one example, a Nikkor 50mm f/1.8 AIS lens:

This lens is a classic manual focus normal lens from Nikon. It is compact, reasonably good optically, and cheap. As seen above, it is connected to a Micro Four Thirds adapter, so that it can be used on M4/3 cameras.

In the image above, the focus ring is set to about 7 meters, 22 feet. The aperture ring is set to f/11. The silver ring in the middle features a crude DOF scale. Notice that the aperture f/11 is set in a yellow colour. There are two yellow markings in the DOF scale as well, indicating the near and far limits of the depth of focus. As the lens is set above, the image is in focus from about 4 meters up until infinity (the rotated 8 sign). Hence, in this case, 4 meters is referred to as the hyperfocal distance for this lens, using the aperture f/11. If I had set the aperture to f/22, the hyperfocal distance would be 2 meters.

Very few Four Thirds and Micro Four Thirds lenses feature any focus scale at all. And even fewer feature a DOF scale. One notable exception is the Olympus M.Zuiko Digital 12mm f/2 wide angle lens, which has both a focus scale and a DOF scale, a first for a Micro Four Thirds lens.

With other lenses, you must investigate the depth of field by looking it up on the Internet. There are a number of online DOF calculators out there, you can find them by searching for the term "dof calculator".

Using the online DOF calculators, you will find that the depth of field depends on the aperture (as we have seen above), the focus distance, the focal length, the size of the sensor, and the circle of confusion. The last term may sound a bit strange, but it simply says how strict the definition of "in focus" is. If you use a large circle of confusion, this means that you are not very strict about what you consider to be proper focus, and the depth of field will be fairly large. And vice versa.

Setting the aperture to affect the DOF

Based on what you have read above, or perhaps this was known to you already, setting a large aperture gives you a small depth of focus, and vice versa. This can be illustrated with an example.

For this example, I used the Pentax FA50, a 50mm f/1.4 film era lens. It is an autofocus lens, but when used with an adapter on the GH2 camera, the focus and aperture must be operated manually. It also has a focus scale and a simple DOF scale.

This lens is quite cheap, and is considered to be reasonably good. It has later been discontinued, and replaced by a newer 55mm f/1.4 lens, which is the portrait lens for Pentax DSLR cameras at the moment.

Using the lens on a GH2 camera, I took this series of images (click to enlarge them):

f/1.4

f/2

f/2.8

f/4

f/5.6

f/8

f/11

f/16

f/22

As you can see, the focus was set on the first plank, to the left. With the largest aperture, f/1.4, the depth of field is very thin, and only the tip of the plank is in focus. As the aperture gets smaller, more and more comes into focus.

A smaller aperture not only makes the depth of focus wider, it generally also improves the optical qualities of the lens. Generally, the sharpness and vignetting characteristics improve as you stop the lens down. However, due to diffraction, this rule does not apply for the smallest apertures. Usually, the optimal aperture in terms of sharpness is around f/5.6-8, due to diffraction effect at smaller apertures.

However, if you need very deep depth of focus (DOF), I think you should still consider using very small apertures, like f/16, despite the negative impacts of diffraction. As long as you don't print very large copies, the diffraction effects are generally not very disturbing.

In this example series, the out of focus appears to be quite ok, so it makes sense to say that the bokeh is pleasing. However, this example was perhaps not the best if the goal was to evaluate the bokeh. Let's look at another example.

Out of focus highlights

The most challenging out of focus type for a lens to handle, tends to be small highlights in the background (or in the foreground). I've made one such example. Here, the focus is set on the centre of the frame. There are out of focus highlights in the background, due to rays of the sun hitting the foliage:

f/1.4

f/2.8

f/5.6

In this case, we see clearly that at the largest aperture, the out of focus highlights are being rendered like small donuts. We say that the bokeh has ringing effects. Since the human eye/brain is very keen to find edges, this ringing effect is very distracting. The eye is constantly drawn to the background, which was not the intention. After all, the background was left out of focus to make it less dominating. So you can see that this is a highly undesired bokeh type.

The donut-shaped bokeh is typical of mirror tele lenses, also referred to as catadioptric telephoto lenses. In fact, this side effect of mirror lenses is one of the reasons why this type of lenses has not become very popular.

For the Pentax FA50 lens used here, the problem appears to be mostly for the very large apertures. Here is an enlargement of the top left corner for the apertures f/1.4-4:

Conclusion

With the latest example of poor bokeh, a short summary of this first article in the series about bokeh is:

One advantage of large sensor camera systems like Micro Four Thirds is the possibility for selective focus, letting the background or foreground go out of focus to make it less distracting.

However, look out for the bokeh, the rendering of the out of focus areas. The bokeh may have artifacts which makes the out of focus areas stand out, rather than blur, which is normally the intention.

Getting an adapter and a large aperture legacy normal lens is a common way to explore the area of thin depth of focus (DOF). But if the lens produces bokeh which is distracting at the large aperture, you may not be able to use it anyway. So it pays to research this aspect before buying.

GH2, built-in flash for macro use

2011-07-28T23:17:00.003+01:00

Lightning is critical for macro photography. To illustrate this, I will present a scene I tried to photograph. I used the Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 Macro lens. To make sure I used the maximum magnification, I selected manual focus (MF), and moved the focus ring until I reached the closest focus distance. Then I placed the camera so that the subject came in focus. This way, I was sure that I used 1:1 macro, which means that the subject is the same size as the sensor area, 17.3mm x 13.0mm.

As a test subject, I originally intended to use a bee. However, I found that chasing a bee around while it was visiting flowers, was much too difficult. Therefore, I found a bee that had been killed by a spider's web. With the bee being suspended, it was much easier to photograph in a controlled fashion.

First, let's consider what aperture to use. The PL45 lens has a maximum aperture of f/2.8, which has been criticized as being too small. Many would have preferred it to be f/2, to make the lens more useful for portraits. In this case, I want to have some depth of field, so I try to set it to f/5.6, a point at which many Micro Four Thirds lenses reach their optimum performance.

Here is the image at f/5.6, 1/60s, ISO 3200:

As you can see, the image is in fact not very good. One wing is in focus, the other is not. The rear part of the bee is in focus, but not the front. We can easily conclude that the depth of focus is too thin: Only parts of the insect is in focus.

To get a better depth of field, let's set the aperture to f/13. Some may worry that f/13 is too small, and will give some dullness due to diffraction. That is true, but as long as you don't make a big magnification of the print, that should not be a problem. For web use, f/13 is no problem at all, and you could even try to use f/16 if needed. I have studied the diffraction effects here.

I took ten images at f/13, 1/15s, ISO 3200, and this one is the most successful:

There are some problems here. First, you can see that the image is not framed very well. I was handholding the camera, which makes framing hard. Also, while the image has much better depth of focus than the previous, it now has some motion blur effects. The shutter speed, 1/15s, is much too slow to handhold the camera, even with Optical Image Stabilization (OIS). Finally, the high ISO at 3200 makes the image a bit noisy.

There is an easy way to solve all these problems: Just use the built-in flash. It turns out that the small built-in flash does cover the entire frame when using the PL45 lens at the closest focus range. The illustration below explains why.

In the illustration, a LEGO figure is placed at the minimum focus distance of the lens. At 1:1 magnification, the distance from the front lens element is 7cm. The built-in flash covers the focal length of 14mm, which corresponds to 75° diagonal field of view.

The resulting image is this:

As you can see, the entire image frame is illuminated by the built-in flash, even at maximum magnification.

A note about the lens hood: I don't like the supplied hood. It is much too wide, and does not do a good job at keeping out stray light. So I made my own hood, composed out of three elements: A 46mm stand off ring (glassless filter), a 46mm-37mm step down ring, and finally a 37mm-28mm step down ring. This gives the ultimate protection against stray light (in my opinion), and also good protection against objects touching the front lens element accidentally.

If you use the original hood, the light from the flash will be blocked by the hood, and you cannot use the built-in flash with macro images.

Back to our bee example. Here is the same image taken with the on-board flash, at f/13, 1/60s, ISO 160:

Using the flash allows for base ISO (160), and there is no problem with camera shake. The flash light is very quick, and freezes the image instantly. We clearly see that this image is much more sharp.

On the other hand, this method is not perfect for macro images: We see that the background has become very dark. This is because the flash light spreads out, and becomes less powerful for the background at a larger distance. Also, the flash light coming from a single light source does give a "flatness" to the image, which is not optimal. The nature of the image changes completely when using the flash.

Using the built-in flash for macro is a quick and easy way to get usable macro images.