DOF - Does it need fixing?

Digital photography has caused many people to rethink how they approach picture taking. At the start everything seemed new and there was a lot to learn very quickly. But after a while most of us thought we had a pretty good grip on the situation and started to relax. But you can't relax for very long. Every now and again someone comes up with something that makes you feel that you hadn't considered every aspect, or that's how it is for me anyway.

An article (actually two) that did this for me recently appeared on The Luminous Landscape, entitled "Focusing in the Digital Era" by Gary Ferguson. In brief it says that depth of field (DOF) with digital cameras can't always be approached the way it was in the days of film (it says a lot more than that - go read). Part of the content came as no surprise. Depth of field scales on lenses designed for film will not be a good guide if we are making substantially larger prints. But that is just down to the maximum acceptable size of circles of confusion (if that confuses you read "Understanding Depth of Field", or even better read chapter 3 of "Basic Photography" by Michael Langford).

As is so often the case, the proof of the pudding is in the eating. So I started to look again at some of my images with this new information still ringing in my ears. Would they be inadequate in the DOF department? Had I just not noticed in my infatuation with this new(ish) digital medium? I have to tell you I was a bit nervous when I started checking. I don't think I need have been. So far I have not found any of my images spoilt by inadequate depth of field (spoilt by plenty of other things though), but I shall keep watching.

So is this a case of "if it ain't broken don't fix it", or was Gary Ferguson drawing out attention to a previously unknown danger. My feeling is that the truth lies somewhere in between, and that his suggestions (particularly regarding infinity focussing) can be seen as another tool in our armoury of techniques, that will be useful when the right circumstances arise.

Picture taken in Granada, September 2006