ok, just to make a fool of myself, I tried to play with numbers I don't understand,namely film RMS.
Tmax 100 is announced at RMS=8, while TX is 17.
a 6x9 neg requires ~2.5 less enlargement than a 35mm frame, thus it seems that in terms of grain effects, a TX on 6x9 has much more grain than a tmax 100 frame in 35mm (each RMS unit multiplies whatever is measured in the grain by a factor of two, right?)
Now that I have made clear that I understand nothing about that stuff, can someone correct me so we learn something today?😉
Note that RMS is a measure of grain, not resolving power.
For resolution you need to look at the film's MTF data. TMAX100 is indeed spectactular, Fuji ACROS is equivalent, and I'd venture to guess that Delta 100 is right in there with the others. Assuming that the camera is held stable and shutter/mirror movement are well-damped, the next most important cause of image blur is usually inaccurate focus. After that, it's film flatness. 35mm generally does better than MF for flatness, which helps 35 to close some (but not all) of the gap with MF. Another thing that can wreck 35mm sharpness is overexposure/overdevelopment. Thin negatives are generally sharper. This is often overlooked.
Assuming you've got all of that under control, you then need to get the detail back
out of the negative. It's a
lot easier to get good enlargements from MF negatives than from 35mm, but with good gear and technique it can be done. Holding the film flat is critical. I love the half-glass carrier for the V35 enlarger.
If you're scanning, MF wins again, and in a big way.
Really it's at the enlarging/scanning stage where MF has the biggest advantages. But 35 can be awfully good with exacting technique. Here's one of my better examples: ACROS developed in XTOL 1+1, scanned on a Polaroid 4000. Click on the picture to see bigger versions of same. Note that scanning tends to accentuate grain vs. enlargements, one reason why MF scans look better than 35. A drum scan would be better, and a good enlargement better still. Even so there is a
lot of detail in this image.
My impression of carefully-handled ACROS is that it can approach the quality of Tri-X or HP5 shot on 645 format. TMAX400-2 on 645 would probably be superior. Soon I'll be out of Neopan 400, and ACROS and TMAX400-2 will be my exclusive choices for 35mm B&W.
