Quote Originally Posted by MatthewDunn View Post
But seriously, the difference in digital, it strikes me, is that if I set my 5dii to ISO 100, I know that is correct. I don't have to worry about figuring out whether a 5dii is really at ISO when I set it at ISO 100. Perhaps this thread is mis-titled, because I think I get the basic tenets of the ZS. It's more how I get to a place where I can use it. In other words, I think it's the generation of personal EI without access to a sensitrometer that has me confused. And that is where things seem different than digital. I am shooting FP4+, but is it really ISO 125 and how do I methodically go about figuring that out?
Well, that's both true and not true. With digital (and I could be wrong; I lurk at some digital oriented sites though), it's like you've committed to a particular film when you bought that model with that sensor. Yes, anything you do with that camera will be consistent to itself. But a 5dii at iso100 might not be exactly the same as the equivalent model from a different company. That's all it is with film - you're changing the sensor each time you choose a different film. While there might be smaller differences between the various Canon, Nikon, and Pentax models as compared to differences between Acros, FP4, and TMax100, there are still differences. And those differences at least partly come down to how you use them, develop them, and print them. The variables that exist can have a more visible effect with film.
And don't forget that many differences seen by the photographers (both film and digital) are NOT seen by the average person looking at the same images.