Quote Originally Posted by Claire Senft
However, any lens that reaches its best performance at f 6 can not out perform a lens that reaches its best performance at a wider aperture..this is not my opinion this is the laws of physics and light.


If one wants to make 15x or bigger enlargements than the best (2) lenses ever released into general commerce are the 40mm f 5.6 Zeiss S-Biogon and the 60mm S-Orthoplanar.
If a lens that reaches best performance at a wider aperture is always better then wouldn't the 40mm f/5.6 Zeiss be a bad lens? Or does it also have to do with magnification factors? Also what if the best performance of one lens at say f/5.6 is worse than the Leitz at f/6--wouldn't it still be outperformed by the Leitz? I have never experienced such massive diffraction as you are talking about with a 50mm enlarger lens (granted I use them at f/5.6-8)

I'm not meaning to be argumentative, but I'm working on <2 hours of sleep and I am not following the logic.