Depth of Field It's one of those things the photographer has to deal with all the time. Mostly, I play it by eye, so to speak. There are times, however, when the technical demands of a session overwhelm the visible, and I have to ask, "How does it work?" In the transition from film-based photography to digital "recording," it helps me to work with geometry and physics, even if just a little. This is my latest effort to figure it out.