One of the coolest things I learned when I got started with photography was the use of the depth of field scales that came engraved in my lenses. With these I was able to take a picture in which both a friend and the trees in the background looked sharp. For this I just had to make sure the distances to both of them were within the range defined by the depth of field markings in my lens… awesome!
If I were to keep both a nearby subject and a distant mountain sharp I would align the depth of field marks for the f/stop I was using with the infinity mark on the focusing ring and then read the shortest distance at which I could have a closest subject appear sharp. If I needed more depth of field (the range of distances at which things look sharp in the print) I would increase the f/stop as needed… I was on a roll!
Modern lenses unfortunately have focusing rings that don’t turn as much as older lenses do and depth of field scales are too small to be useful. Two-ring zoom lenses cannot have them as the scales depend on the focal length… in a word: they are gone. Some people probably have never seen them.
Website depth of field calculators and smart phone apps have tried to save the day and some claim are even better than the depth of field scales in the lenses. Unfortunately, both the calculators and the lens’s scales have been the target of a lot of criticism recently as they seem to fail in delivering the promised sharpness. Some people claim this is because depth of field scales were based on older films and printing papers. Other say they were never good anyway. Still, a lot of photographers bravely defend them… and even Ansel Adams used them.
So, who’s right? I have made plenty of landscape images where I get sharpness from my closest subject to infinity so there must be some truth to depth of field calculations. However, I have made other photos that don’t look as good. I have tried hard to understand what is going on and I believe I have an answer.
What I want to do is to give you enough data (images that is) so you can come to your own conclusions about all this. Maybe you will agree with me, maybe not, let’s blog and see. I cannot write long posts (I surely have undiagnosed ADD) and there are many things to cover. If I have sparked your curiosity stay tuned for my next post…
a peek preview:
Here is a link to a picture you can download to see depth of field scales or hyperfocal distance tables in action. It contains one inch square sections of an 8×10 inch enlargement. I will explain what the jargon means in my next post but, if you already know the stuff, the picture will tell you how to get the depth of field and the image quality you want. Filename is “full-frame-28mmf11-hyperfocal-8×10”
The first column has crops of Nikon D810 full frame images taken with a 28 mm lens focused at the hyperfocal distance for f/8 and a 0.03 µm confusion circle, then images with the lens stopped down in one f/stop increments. The second column has the lens focused on the distant trees and the same f/stop values. Print in A4 or US Letter sized photo paper (it corresponds to an 8 x 10 inches original picture so each crop is 1×1 in). I processed the photos with Lightroom 5’s default sharpening and settings. Examine from a 13 in distance in good light. On my next post I will offer similar photos for a cropped sensor camera and different final print sizes.