I have been testing some new LF lenses. Based on the results on Chris Perez's we b site, I decided to use TMX 100 for the tests. At the recommendation of local " experts" I used Tmax developer, at 1:4 dilution, 72 degrees for 7 min, and rated the film at EI 100.
I am using the standard USAF lens charts at a 50:1 distance to emulate infinity.
What I am finding is that 1) (the good news) is my 55mm Apo-Grandagon clearly re solves 70 lp/mm, and 2) (the subject of this question) beyond about 70 lp/mm it appears that grain size really plays havoc with resolution.
On paper, these films are supposed to be able to resolve > 100 lp/mm at high con trast, and although my charts aren't 1000:1 contrast, I cannot see how, with the size grain I observe, this film could ever resolve 100+ lp/mm.
Am I too stringent on my definition of resolution? I expect to see ightlines sep arated along their entire length by a dark line.
Is my developer/time/temperature giving me too much grain?
I am using a 40x Zeiss stereomicroscope to view the negs, so that's not the weak link.
Thanks for any feedback.
Bookmarks