The film vs digital argument has been going on since DSLRs first hit the market a couple of decades ago. But it doesn’t seem to be dying any time soon, especially with films popularity growing again. One of the big debates between the two formats that regularly pops up is that of dynamic range.
So, photographer Bill Lawson put it to the test. He shot some Kodak T-Max 100 in a Nikon N90s vs the more recent Nikon D750 DSLR using the Nikon 135mm f/2 AF-D DC lens on both to see how they compare.
There are a few things to bear in mind with this test. Bill is shooting black and white negative film in this test, which typically has the highest latitude amongst film, particularly for overexposure. Had he used colour negative film or slide film, the results would probably be somewhat different. It was also developed in Kodak D-76 developer. Again, the results might be different had he used something else, like Ilfotech DD-X. It’s also as much a test of the scanner used as it is the film itself.
Bill shot 21 images with each camera. A correctly exposed shot, then ten images underexposed and ten images overexposed, each one stop apart. And the results are interesting, but not unexpected – especially for those who’ve shot negative film before.
The Kodak TMAX film offered the higher dynamic range overall, with around 13 stops of acceptable (to Bill) exposure latitude. Everything from 2 stops underexposed to a crazy 10 stops overexposed worked quite well. With digital, it was slightly less at around 9 stops, with 6 stops underexposed to 2 stops overexposed looking good.
As the results indicate, and as the word “negative” implies, digital and negative film work in opposite ways. With film, overexposing the shot results in very little degradation of the image, even in the highlights, while underexposing will kill shadow detail very quickly. With digital, it’s the other way around. Underexposing offers a minimal amount of degradation for a few stops while overexposing loses detail almost immediately.
So, in short, and speaking generally, with digital, shoot to record maximum highlight detail (underexpose if needed), and then recover the shadows in post. With negative film, shoot to record maximum shadow detail (overexpose if needed) and develop for the highlights in post.