When capturing portraits of animals, I focus on the eyes. Viewers tend to lock in on the eyes first, so it's important that the eyes are in sharp focus. Then, I usually strive to select an aperture that will provide enough depth of field so that the nose is sharp as well. However, it's a balancing act with the aperture selection. Although I usually want the nose to be in focus, I also tend to prefer a soft background.

Last week, I visited the kangaroo exhibit at the Brookfield Zoo. While capturing this closeup portrait, I selected the widest aperture on my 300mm lens (f/2.8). This kangaroo is a small animal (no more than 4 feet tall) and he was positioned about 30 feet from me. So, I figured that the depth of field would certainly be wide enough to get both the eyes and the nose in focus.

I was wrong!

KangarooWestern Gray Kangaroo (Macropus fuliginosus) at the Brookfield Zoo in Brookfield, Illinois on May 15, 2014. The eyes are razor sharp, but the nose is not in focus. This crop might help make this easier to see:

I checked the display on the back of my camera immediately after capturing this image and noticed the problem. I narrowed my aperture to f/5.6 and then to f/7.1. That solved my depth of field problem, but the kangaroo never made eye contact with me again!

I found it hard to believe that the depth of field wasn't adequate to get both the eyes and nose of this kangaroo in focus. He's such a small animal and he was positioned a good distance from the lens. But, I failed to account for two factors:

• This kangaroo has a very long nose! That can be seen better in profile.
• The depth of field is surprisingly narrow given the lens and aperture that I chose.

To check the depth of field, I referred to an online depth of field calculator. I also have a DOF calculator on my phone. I should have used it! After entering in the various factors (i.e., camera, lens, aperture, distance), the calculator does in fact confirm the very narrow depth of field for acceptable focus--0.25 feet, or only 3 inches of depth!

But, it's always good to keep shooting. The more I shoot, the more issues like this come to light and stay top of mind. So, the next time I shoot in a similar situation, perhaps a family pet, I don't plan on making the same mistake again.