How Deep is Your Field?

My camera mostly stays in Aperture Priority mode. Sometimes I'll shoot in full manual, occasionally in Shutter Priority; but in the main I shoot A_v. I think the photograph for this post helps explain my reasoning.

I love to control the depth of field in my photos. It helps to focus the viewer's attention on the main subject by reducing background clutter and distractions. With a large enough aperture it's possible to turn the most cluttered background into a blurred field of color and vague shapes and bokeh. In the case of this Eastern Swallowtail butterfly (Papilio glaucus), that background looks almost impressionistic and forces the butterfly and the thistle it landed on to pop out into the foreground.

Eastern Swallowtail Butterfly

Because I shot this picture several years ago, before I got my current DSLR, I couldn't get the aperture quite as large as I wanted, so I enhanced the blur very slightly in Photoshop. Other than that, I cropped the picture for composition and corrected the color.

This picture was another one of those lucky shots where I just happened to have my camera with me on a late summer walk. I saw this butterfly flitting from flower to flower in the thistle growing in a ditch near my house and I slowly stalked it until it landed in just the right spot, in the sun on a nicely placed flower and captured it with it's wings spread wide. I was very happy with how this turned out and think that the slight imperfections on the insects wings adds to the interest; sometimes a subject can be too perfect...

Most nature photos - in my opinion, unless you are shooting landscapes can benefit from narrowing and controlling the depth of field with aperture. But you really have to watch your focus and you may have to trade off the actual depth of field with your ability to control exposure. If you can do it right, though, the effort is worth it. If your camera stays in Auto mode, explore the other modes. You'll be amazed at how different - and better - your pictures can be.