Get your copy of HDR Photography: Photo Workshop at Amazon UK.

When taking a photograph, there are three primary factors determining how it is exposed; aperture, shutter speed and ISO.   Aperture refers to the size of the opening through which light is transmitted through a lens, shutter speed is a misnomer referring to the length of time the digital imaging sensor in your camera is exposed to an image and ISO refers to amount of amplification applied to the light information received by the sensor.

In typical, well lit circumstances, a photograph is deemed well exposed when there’s a distribution of tones without any unintentional clipping of shadows or highlights which result in lost image detail.  This isn’t always possible to achieve especially when a scene contains a greater dynamic range than what an imaging sensor can record.

As with any rule in photography, there are exceptions as well as the bending of rules in order to achieve the final desired result, but in many cases the best exposure is one where all of the determining factors are balanced to achieve a spread of tones without any clipping.  It’s important to reiterate that this isn’t necessarily the exposure you would want for the image you wish to create, but is more of an average for averagely lit scenes.

There are three main factors under a photographer’s control which determine how a photograph is exposed; aperture, shutter speed and ISO.

An analogy for the concept of exposure is to think of taking photographs as filling a bucket.  Instead of light, our medium is water.  To substitute the lens, we have a hosepipe.  The size of the diameter of the hosepipe is our aperture and in place of the shutter, we have a tap.  Our bucket is therefore the ISO.

Rather than dealing with absolute values of litres and gallons, let’s suppose the non-clipped exposure for a given ISO is a bucket which is filled exactly to the brim without any spillage.  This is useful in that it immediately tells us that for a given size of bucket (ISO value) we require a specific amount of water (light) in order to fill it (achieve an average exposure).

One slight twist of logic is with our sizing of buckets.  The larger the bucket number, the smaller the bucket actually is.  Just as the larger the ISO value, the less light we require to achieve an average exposure.

So, exactly how much water is required to fill any particular bucket?  What diameter hosepipe do we require?  How long should we keep the tap open?  As with filling a real-life bucket, we can vary the diameter of the hosepipe as long as we vary the length of time we keep the tap open proportionally.  Likewise, we can fill a bucket by leaving the tap open for longer when we’re using a smaller diameter hosepipe or for a shorter period if we’re using a larger diameter hosepipe.

By balancing the diameter of the hosepipe with the length of time the tap remains open, we control the total volume of water that travels through it.  As long as that volume is enough to fill the bucket and no more then we will achieve our goal.

Going back to the world of photography, for a given ISO setting, the digital imaging sensor inside your camera requires a certain volume of light in order to achieve a non-clipped exposure.  In terms of exposure, it doesn’t matter whether you use a larger or smaller aperture as long as the length of time the shutter is kept open is long enough for the required volume of light to reach the sensor.  Too little light results in an underexposed image, just as too little water results in an under-filled bucket.  Too much water results in over filling, just as too much light results in overexposure.

There are considerations and consequences of using different apertures and shutter speeds, but it’s the balancing of these factors which determine exposure.  That’s why taking a photograph is just like filling a bucket.

Now, Lark Lane is an interesting street in itself with a very strong community feel.  The main road is lined with cafes, bars, restaurants, beauty salons, everyday shops as well as novelty shops and even a tattoo parlour.  Looking upwards, you get a sense of Lark Lane’s history as above the present day shop signage sits an indication of what was there before.  Off the main road are a colourful mixture of residential streets most of which are terraced, but there are the occasional surprises to be found.

The type of photography for the day was clearly a mixture of documentary, street and candid portraiture.  Areas of photography that I’ve not really ventured too deeply into before.  So, the day promised to be a fresh challenge for me which is one of the reasons why I joined the Fab Collective; to challenge myself and push my photography to where it’s never been before.

The day was immensely fun.  Not only were there some very friendly, approachable people in Lark Lane who were obviously very proud of their heritage, but it was also good to get to know some of the other Fabbers a little better.

There were plenty of photo opportunities to be had, both in and out of the farmers market.  As someone who has been used to mostly landscape photography, I was used to taking my time to set up shots and waiting for moments to occur.  Often, if you miss a moment in landscape photography there’s a chance you can simply wait for it to return.  I found that this really wasn’t the case with street photography.  Those candid moments when your subject is both interesting and not aware don’t always last and aren’t always repeated.  There were plenty of times during the day when I felt rushed or frustrated because I was too late to realise that an interesting shot had just gone by.

After a good 5 hours shooting up and down the street, I decided to call it a day and head home to process my shots.  Since then, I’ve struggled somewhat with what I took.  Some photos I’ve processed and reprocessed only to result in something which - it’s hard to describe, but - just doesn’t feel right.  Perhaps, the photos I’d taken weren’t particular great to start with.  Perhaps, I don’t really know what the end goal is so processing becomes aimless.  Perhaps, I just don’t (yet) have the ‘eye’ for this type of photography.  Whatever is the reason why, I’ve come away from a great days shoot not really knowing how I feel about the results.

I’ve uploaded some of my shots and will put some forward for the Fab Collective gallery, but I feel I’m on the beginning of a learning and experience curve.  I know this is a good thing and it’s this sort of challenge that I want because, for me, starting at zero is the path to achieving satisfaction.  It’s just not a challenge if it’s too easy!

Success doesn’t come without the risk of failure.

Around the tail end of 2008, a diverse group of Merseyside-based photographers found each other through the power of Flickr and decided they wanted to work together as a collective and put on an exhibition to showcase their work and also the city which brought them together.

Through the months that followed, much discussion took place both online and in real life together.  Through a great team effort, this has resulted in the formation of the Fab Collective and the booking of St. Luke’s church for an exhibition in August 2009.

Since its birth, the Fab Colective have undertaken a number of additional projects as a means of building awareness as well as for an opportunity to take photographs and have some fun.

If you’re in the local area and it’s somewhere with photographic interest, who knows, they might come and visit you!

As far as operating systems went, Windows was what I knew best and what I’d stuck with for many years. Sure, I’d had experience of other operating systems such as Linux, but Windows was what I used to work and play for the majority of the time.

Nowadays, my thirst for more productive time is at an all time high. As a photographer processing lots of relatively large files, having a computer platform that performs and is stable is a high priority. Unfortunately, my main Windows computer had become more and more unreliable as time went on. Having received many glowing first-hand reports on the latest generation of Macs and also from my own experience at Apple stores, I decided it was time leave the annoyances of Windows behind.

That brings me to today. I’ve left behind a large, noisy PC tower to a shiny, quiet, compact MacBook Pro. Not only has the transition been quick, but it’s been easy too. For almost every application I used on Windows, I’ve been able to replace with a Mac equivalent. For the few applications that are currently (Mac versions are under development) Windows only, I’ve still got the option of running them from within a virtual Windows installation running within the Mac OS.

The operating system is friendly and just lets me get on doing what I want to do rather than having to mess about with too many settings and having to install drivers. This means that I don’t need to put on my technical hat to and I don’t feel the need to swear at the computer because a window or dialogue from another application has just rudely popped in front of the one I was using and intercepted the keystrokes I’d just made.

All of my peripherals, bar my ancient scanner which required a driver download, worked when I plugged them in. Connecting to wireless networks has been completely painless. Photoshop, Lightroom and Photomatix are all running faster than I ever had them on Windows. Even the memory issues that plagued Lightroom for Windows seem to have been left behind. The integration between these three mainstay applications also seems to be tighter on a Mac. Images can be exported from Lightroom to be automatically fed into Photomatix and back again. No need to go digging in Explorer!

As I still have the monitor I used with my PC, I simply plug this into my MacBook Pro (requires an adapter) and I get a very useful second display which can be used to extend the desktop or can serve its own purpose e.g. to provide an alternative view of images in Lightroom.

Then of course, the software that allows me to connect my Canon 5D to a computer also comes in a Mac flavour although I’m one who prefers to transfer images directly from the memory card using a USB card reader.

The downsides of migrating to Mac? There’s obviously the cost of such a migration to consider. Apple Macs aren’t cheap and then there’s the added cost of software to consider although some developers will allow you to transfer licenses for such a transition. The user interface is different from Windows although there are elements to it which are similar. You can still browse through the file system, you still have windows which you can maximise, minimise and close, etc. Some applications have a slightly different layout on Mac from what they have on Windows. The menu layout in Firefox being an example, but it’s not something that takes very long to get used to.

As I mentioned earlier, there were a few applications which I simply couldn’t find Mac-compatible alternatives which were as good.  For these, I had to turn to a virtual installation of Windows XP using VMWare’s Fusion.  It’s worth noting that installing Windows XP via Fusion was easier than installing it on a real computer because Fusion handles all of the driver side of things and even sets up the network connection for you.

The most technical issue I came across was to do with the fact that Mac OS X can’t natively write to NTFS formatted drives which caused a slight headache as that’s how I’d formatted my external hard drives. Fortunately, a solution was just a quick Google away in the form of MacFUSE and NTFS-3G.

As an experienced, computer literate user, my migration from Windows to Mac has been smooth and uneventful.  From the perspective of user-friendliness and stability, Mac OS X has been very good at keeping the gears and levers out of the way of my productivity.  For others who are less confident with computers, I think the move to Mac is still a good one as the benefits on offer after the move has been completed are very worthwhile.

As I’ve seen and heard from many Mac users, Macs just work.  I’m certainly not going to argue with them.

Anyway, the path from 40D to 5D is considered by most to be an upward one due to the increase in sensor size even though the 40D is 2 years the junior in terms of release dates.

Okay, bigger sensor size.  What exactly does that mean?

Technically speaking, DPReview provides the following information about the difference in 40D and 5D sensors:

Canon EOS 40D

• 10.1 million effective pixels
• 3.1 MP/cm² pixel density
• 22.2 x 14.8 mm CMOS sensor

Canon EOS 5D

• 12.7 million effective pixels
• 1.5 MP/cm² pixel density
• 35.8 x 23.9 mm CMOS sensor

These spec’s tell us that the 5D’s sensor has a much greater area (855.62mm²) to capture light than the 40D’s (328.56mm²), approximately 20% more pixels, but that the pixels are spread less densely.  We know that the individual photosites which collect the light from the scene are larger.  This means they can collect more light than the photosites in the 40D sensor within the same period of time.  More light means more information about the scene and less pixel density means each photosite is exposed to less noise-causing interference from other photosites.

In real-world terms, this equates to:

• Greater dynamic range
• Less image noise especially at higher ISO settings
• Easier to blur backgrounds due to shallower depth of field (no field of view crop factor)

For me and the type of photography I engage in, this means the sensor in the 5D is a better sensor than that in the 40D.  There are, of course, other differences between the two camera bodies, but none are as important to me than the sensor.  Now, with that out of the way, have I actually noticed any difference in the photos I take?  The answer to that is most definitely yes!

In terms of user experience, some of the differences I noted 5 months ago are still prominent.  The biggest ‘downgrade’ for me in terms of user experience is the lack of a permanent display of the current ISO setting in the viewfinder.  Accidentally shooting at ISO 3200 when ISO 400 would have been a better choice is just too easy to do.  Also, more of an issue is the amount of sensor cleaning that can be required.  A lack of an automatic sensor cleaning feature costs time and money spent on cleaning tools.  Less annoying are the lack of Live View and the smaller LCD on the back of the camera.

All in all, I’m very happy with the move I made from the 40D to the 5D.  Even though the 5D Mark II has been release, I still feel very content with my Mark I.  When teamed up with a selection of good quality lenses, it’s a combination I find difficult to falter.

Here’s a link to my review of one of Damien’s earlier DVDs - Using Natural Light on Location DVD by Damien Lovegrove

Amongst our plans was a trek to the Skiddaw summit and another to Helvellyn, but on each occasion the weather stopped us short.  Fortunately, we did have one day that was clear enough for us to talk up Catbells.  The views from up there are amongst my favourite in the Lakes and this visit made it even more so.

I’m looking forward to going back!

Snowy Catbells from William Lee on Vimeo.

If you’re on Twitter, why not look me up!

http://twitter.com/DigitalRelish