Well, My most basic description would be this: Depth of field is the area within your shot that appears in focus. Everything that is out of focus is outside of your depth of field.

I’ve labelled this photo to show you what I mean – just click on it to see the . . . → Read More: A quick and practical guide to Depth of Field]]> What is depth of field (DoF)?

Well, My most basic description would be this: Depth of field is the area within your shot that appears in focus. Everything that is out of focus is outside of your depth of field.

I’ve labelled this photo to show you what I mean – just click on it to see the full-sized version.

OK, so now we know what DoF is, but what controls where the DoF starts and finishes? The theory behind DoF is really quite complex and can be somewhat overwhelming for a beginner. My intention here isn’t to get into the physics of DoF, but rather discuss how to use it in your photos, so for this reason I’m going to simplify it dramatically. I’ll include a link at the bottom of the page for those of you who have a greater interest in physics.

DoF is determined by the aperture setting of the lens, the effective focal length of the lens, and the distance of the subject from the camera. There is another determining factor called the “circle of confusion”, but it’s relative, so we won’t get into that in this post. Once again, see the link at the bottom of the page for more info.

So how would I adjust the DoF for a particular shot? First and foremost I would need to have a good idea about how I want the resulting shot to appear. Do I want a sharp focus on just my subject? Or maybe I would prefer some or all of the background to be clear too? The answer to these questions will determine how the shot will be set up.

For a shallow DoF where only the subject is in focus, I would have the subject very close, maybe only 2 Metres away from the camera. I would adjust the focal length as desired before setting the focus on my subject. Finally, I would then set my aperture and shutter speed. Generally speaking, the higher the f-number, the larger the DoF for any given focal length, so in this instance, I would want a low f-number. A low f-number means the aperture would be wide open, so a relatively fast shutter speed would be required.

In contrast, if I wanted to include something like mountains or buildings in the background and have them all within an acceptable range of focus, I would have my subject further away from the camera. Once again I would compose the shot, adjust the focal length and focus before setting the f-number and the shutter speed. In this case though, because I wanted a deeper DoF, I would set my f-number high – perhaps as high as my camera would allow. This will reduce the aperture size right down to a small opening so a much slower shutter speed would be required. Use a tripod if necessary.

OK, so here’s a test you can do yourself. This test will work best if there’s a distant background – go outside and set your camera on a tripod. Set your subject 1 or 2 metres from the camera and set your lens to a “normal” focal length (say, around 50mm for a 35mm camera). Your camera should be in manual or aperture priority mode. Get your subject into sharp focus. Now, choose the lowest f-number available – adjust your shutter speed accordingly and take the shot.

For the second part of the test, move your subject (or camera) further away – we’ll go with 10 metres this time. Leave your focal length the same as in the last shot. Set your focus on your subject and set your f-number to the highest number available and once again set your shutter speed accordingly. Take the shot.

Tell me about your results. How did the two shots differ?

BTW – Here are the theory links:

Depth of Field

Focal Length

Circle of Confusion

Aperture

Not to . . . → Read More: Experimenting with night photography]]> On the way home from work one night this week I noticed the moon looked particularly spectacular. I couldn’t wait to get home to grab my camera! Unfortunately, by the time I had arrived home clouds had obscured the moon completely, and I realised that from my back deck, it was also behind the trees.

Not to worry! I thought I’d wait it out and see what would happen in the next couple of hours. Hopefully, the moon would rise enough to be seen. As luck would have it, the clouds started to clear and the moon did get a little higher in the sky. By about 9pm it was still behind the trees but looked quite interesting, so I started experimenting.

The following photos are just a few examples of the results. All were taken with aperture (f-stop) at 4, and a focal length of 28mm. There were two things different in each shot. The shutter speed, and the obscurity of the moon behind the clouds.

Here’s the first shot. The shutter speed was set to 5 seconds. You’ll notice a bit of noise in the black areas due to the film being under exposed. The moon is hiding behind some cloud here so the light’s quite low.

The second shot is “the one”. This one was certainly the best of the three, and probably the best out of the whole set from that night. I’m really quite happy with the exposure. The moon was fully uncovered and shutter speed was 10 seconds. There’s only a tiny bit of noise in the black areas. You can find the final version of this in the “Recent Film Images” gallery with only some minor cropping and a frame. I love the slight motion of the cloud and the crystalline blue moonlight.

Finally, the worst shot. The moon was obscured here again, and the shutter speed was a nasty 2 seconds – way too short for the amount of light available. The results speak for themselves. The black areas are extremely noisy, and the overall image isn’t appealing.

Well, that’s it for this post. I shot off a whole role of film today on a pair of Rainbow Lorikeets that were on my back deck. I’ll get some of those up in the next week or so.

As an example, just by cropping a . . . → Read More: Framing your scene]]> I’ve recently discovered that it’s often better to frame your shot beyond the intended scene or subject. My reasoning for this is that when you include additional scenery in a shot, you have more information in the frame, and this provides more options when it comes to tuning the final product.

As an example, just by cropping a scene creatively, it’s easy to create more interest or to change the way a shot feels by biasing objects toward a particular area of the frame. This can help to draw the eye away from the centre, or at least toward a point of interest. Having the additional information in a frame can also help you clean up some human error that may be evident once your film has been developed.

The following photo will be used as my example in this post. I took this shot at a place called the “V-Wall” at Nambucca Heads on the north coast of NSW, Australia. It’s quite an interesting place. A break wall, a couple of hundred metres long, where various tourists have all left their mark over the past 15 years or so by painting the concrete and stones that have been used to make up the breakwater.

Here’s the original shot – you’ll notice right off the mark that it’s not horizontal, and there’s quite a lot of sky. The following edits aren’t necessarily nice, I’m simply using them to demonstrate a point.

The first thing I will do here is straighten the frame up. I’ve used photoshop to do this for the purposes of this post, but a print could easily be cropped at the correct angle with a guillotine to achieve the same result. This can also be corrected in the darkroom if you’re developing your own prints. I’ll also use this opportunity to cut down the amount of sky visible.

In the next edit, you’ll see that I’ve taken almost all of the sky out of the frame and I’ve remove some of the right-hand side. Did you notice that your eye was drawn up the path toward the people at the end?

This time, I’ve cropped the top right out of the shot, and the people too. This edit draws my attention to the very middle of the path.

And finally, by cropping the right-hand side out of the frame, The large boulders that make up the break wall are now the focus of the shot. I feel compelled to try an read them…

So, in short, my point is this: Always think about including more in your shots than just the subject. You’ll often find that by adjusting visible parts of the shot in post-editing and using some of the additional information, you can make your finished product more intriguing to the viewer.