By Jim Zuckerman
Photographing something as tiny as this green and black poison dart frog from Costa Rica presents a technical and artistic challenge. It is only about an inch and a half long. In order to significantly fill the frame with the amphibian, I had to focus very close to it. This meant that the depth of field would be extremely shallow. So shallow, in fact, that it would be virtually impossible to maintain focus on the entire body. The only way to increase the depth of field would be to use a small lens aperture, but in the shade of the jungle that would force the shutter speed to be too slow, and my fear was that nothing would be sharp at all.
I brought with me a flash bracket by Novoflex that has two flexible arms for holding two flash units. The flash units can be positioned simply be bending the arms, and I wanted one flash on either side of the subject. I figured this would provide a better type of light than on-camera flash. I tried that, but the problem was that the frog was so low to the ground that the light wasn’t illuminating the underside of it. Since a large part of the frog is black, the contrast between the illuminated dorsal area and the very dark ventral section was too much. There was no detail to be seen in the shadow.
The only solution was to use the ambient light that was very soft and diffused. I took the shot with a 50mm macro, 400 ISO, and f/8 (a 100mm macro would have given me a greater working distance – a good thing so I wouldn’t scare the frog as much and it would offer more protection from coming in contact with the poisonous skin – but f/8 on a 100mm lens has less depth of field than f/8 on a 50mm lens). My shutter speed was 1/60th of a second. I couldn’t even use a tripod because even without a center column, the ballhead of my tripod wouldn’t allow me to place the camera low enough for an intimate eye-level portrait. I lay flat on the jungle floor, trying to keep my distance from a mound of fire ants, and used the ground to steady the camera.
After I took several shots, the frog jumped to another platform and I moved with it, shooting a vertical this time. You can see that the camera lens was right at ground level.