First, regardless of format or film type, it takes extra effort and restrictions to acheive higher image quality (grain, sharpness, etc.) That said, Pan F 50 probably won't be any sharper or finer grained than TMAX 100 (IMHO the finest grained silver image B&W film at that speed) or Delta 100 (more distinct grain than TMX). Agfa 25 is a step sharper and finer grained than TMX, of course at a price in speed. Tech Pan is even sharper and virtually grainless (the grains are as small as the wavelength of light) but it's expensive and tricky to expose and process. With the sharpest films 35mm resolution ON THE FILM tops out at about 100-120 lp/mm with normal and short telephoto lenses. With 6x7, which is twice the linear size of 35mm, resolution tops out at 80-90 lp/mm. So 35mm would have to resolve 160-180 lp/mm to be comparable. Not likely. A sharp print viewed at 10" needs about 4 lp/mm to look sharp. If you work out the math you'll see that a 35mm negative needs 64 lp/mm to make a sharp 16x20, entirely possible with careful technique and slow film like Agfa 25. A 6x7 negative would need 32 lp/mm. Posible with most 400 speed films. These figures ignore loss in the enlarger lens. A print with 4 lp/mm will look sharp but a print with 7 lp/mm will look excellent. To make an excellent 16x20 the 35mm negative will need 112 lp/mm. Without a perfect enlarger lens it ain't gonna happen. Bottom line: to make excellently sharp big prints you need a bigger negative.(posted 9341 days ago)I shoot 35mm and 6x6. I find that in terms of grain 100 speed B&W film in 35mm is comparable to 400 speed in 6x6. Regarding color print film Kodak and Fuji have gone to great efforts to make excellent 400 speed films. So to get grain comparable to 400 speed 6x6 film I have to use Ektar 25 (now discontinued dammit!) in 35mm.