The other approach is, that we have to take into account that since the invent of digital photography, the viewing conditions of pictures have changed.
The old tables and tales about DOF assumed a viewing distance of about 25 cm and a picture size of 8x10 inch, about 20x25 cm. In practice people seldom make a 20x25 prints anymore, the smallest larger prints are A4 and often prints are even larger, A3 and up. Did you ever watch people looking at pictures at an exhibition? Many look at a picture and then close in at it and judge sharpness from the closest possible distance, 25 cm or sometimes even less.
Most photographers even almost completely stopped making prints and stare at their screens instead. They often zoom in to 100%. For some reason or another, we tend to do the same with camera’s like the D800, where zooming to 50% gives the same level of detail as zooming to 100% on the D3/S/700. Picture editors do the same or do things that are even worse. They simply zoom in to 200% with their enormous monitors, with a diagonal of 30” or more.
The question is about as old as photography: how do you make pictures that are really sharp, where you can see sharp details not only at one spot, but everywhere?
The answer is simple: we don’t. We never do. We can’t, we cheat. What we call sharp is in fact blurred, what looks like a point is a circle and lines that appear separated are in fact overlapping. That however, makes it easier to make pictures where everything looks sharp, because that’s the only thing we have to worry about: how it looks.
How it looks however, depends on how we look, and that changes in time. In the time when we mainly made our own black and white prints at 8x10” we looked at pictures differently compared to these days of 30” monitors and 100% views.
When it comes to depth of field in the digital age, two approaches are possible. One is, that in digital photography all the old rules still apply and that nothing has changed. People who follow this train of thought, use old tables for DOF and are perfectly happy because they found a simple answer to a complicated question.
Picture data: D800E 1/100s f/4 1600 ISO 14-24/2.8 @ 14 mm.
On Nikon camera's, Nikon lenses and more
By Dré de Man, photographer, journalist, and author of 22 books on digital photography and Nikon camera's