Photography Lesson #3 - Depth of Field

Michelle and I are working our way through a photography class together. This assignment was about playing with lighting and shooting a still life. I came up with three things worth writing about in doing this assignment. My first one is about depth of field.

This is essentially the same picture. I had the camera on a tripod and took the picture with a small aperture (F22) and a large one (F1.8). This made for different shutter speeds but the depth of field change makes it a completely different picture.

This first picture (to me, anyway) is a photo of a the front of my pickup with some tools in front of it. My eye goes right to the Chevy emblem, then to the yellow sander.

Aperture is f/22

I want to show you the same picture with different depth of field. When I look at this picture the pickup more or less goes away. Sure, it's still there but because if it out of focus my eye goes straight to the sander (probably because it's yellow) and from there to the dust mask. The picture becomes something different. It is now a still life picture of tools.

Aperture is f/1.8

Your choices in depth of field have everything about what your picture becomes. I can make you look at different things by using focus, but only if I'm controlling depth of field. When everything is in focus other factors decide where you look.

If you're convinced depth of field is all about controlling where people look, you are not completely right. Depth of field done correctly will make you look where I want you to look but sometimes, when you turn all the control over to the camera you can create a picture that can only be described as "bad". Let me show you what I mean...

If you look at this picture it is just annoying. At first glance you might not even realize why. The composition is wrong because there is too much stuff in the frame and it isn't arranged correctly. As a result the picture is cluttered in confusing. That is annoying but is not as the focus problem.

Your eye is drawn to the yellow sander but it's not in focus. The whole front row is fuzzy and annoying. The dust mask in the back is kind of in focus but even it is off a bit. I half pressed the shutter button 3 times (making it choose different spots to focus on). Ultimately when I took the picture I had let it "choose" to focus on the stripping tool in the right rear corner.

Look at the enlarged version of this picture. The stripping disk is in great focus but it's such a minor part of the composition it does nothing but make this bad picture worse.

In summary, the learning point here is that you can use depth of field to control what folks are looking at in your photographs. Done correctly it's a nice tool for turning your pictures into whatever you want them to be but done wrong it can make your pictures really bad.