Quote Originally Posted by Prof_Pixel View Post
Back several years ago I spent some time comparing lenses for the different formats (35mm, MF, LF) and found that the lens performance (as measured by MTF (Modulation Transfer Function)) fell off considerably as the format size increased. What this means is that you can't directly equate image sharpness to film size - you have to look at the film size and lens quality as a team.
That mirrors what I used to read in books when I was starting in photography, although from a different angle they weren't advocating fine grain developers for LF films and it was less important (in their terms) with MF. It wasn't all books but a high proportion (school library).

But although the lens is important choice of film & developer is just as critical. Kodak themselves put their 3 main B&W developers into perspective in various publications, HC110 is worst over all, D76 a bit better but Xtol is way ahead on all fronts in terms of film speed, finer grain and, sharpness and from my POV tonality. I think they are right as well.

I've seen a lens range (brand) pass all the tests for MTF etc as good as their main competitors only to be totally scrapped because of poor Multi Coating and horrific flare. So I take these kind of test results cautiously.

If you go back over 65+ years to the start of the era of modern coated Lenses then there were many quite pedestrian LF lenses from numerous manufacturers Kodak included. But there were also some superb lens, the 203mm (8") f7.7 Ektar is one example. It's so subjective I used various convertible Schneider Symmmars and with excellent results but their MTF tests wouldn't get that close to the Symmas-S lenses and equivalent
I think there was a "historic perception" that we didn't need lenses of as high a quality for LF as was needed for 35mm or 120, but I've always believed we should have the best a available.

Then we also take for granted the superb quality of modern films forgetting the step changes that took place with each new generation, not so obvious with Kodak nomenclature (after all Tri-X & Plus-X etc first made before WWII) but those of us who use Ilford films remember HP3, HP4, HP5 and now HP5+ for example and there were noticeable improvements between the first 3.

My point is as photographers we are depenent on a number of afctors in achieving high quality and ultimately it's the weakest link in the chain that can let us down.

Ian