I photographed this mountain lion cub at one of my wildlife workshops. The hole in the log framed the cub perfectly, and it's hard to take a bad picture of such an adorable little face. I made one mistake, though. I took this picture with a 300mm f/2.8 Canon telephoto, and the aperture I used was f/3.5. In a shot like this, the entire face of the log has to be as sharp as the cub's face. Because the plane of the cub and the plane of the bark were not equidistant to the camera -- they were about two inches apart -- the entire arch that forms the top of the hole isn't sharp. That doesn't ruin the image, but still I find it visually annoying. My other settings were 1/350 and 320 ISO. I should have taken this picture with an aperture of f/16 to be absolutely sure I had complete depth of field.