Just to give you a reference, below I tested the Pentax Macro 50mm f4 on my Pentax body using Kodak Techpan @ ISO25, ideal shooting condition and setup with a 12233 resolution test chart to provide the detail need to evaluate the overall resolving power of this system.
Full res version -> http://www.fototime.com/8372250EA44CB06/orig.jpg
I did this test on my lenses as I wasn't sure just how good - or bad, they are given that they were not factory new. As you can see from the results above, not even a 36MP Nikon D800 can resolve all the detail this lens can resolve. As a result of this test, I can't determine what is the limiting factor - is it the lens or the film or some other?
I've tested all my Pentax prime lenses - bought used, and they will not be the limiting factor in achieving all the detail that the scene has.
In terms of film, unless you are shooting microfiche film, Tmax at 200 LPMM is the film with best resolution, if a lens can resolve 200 LPMM then it is sharp enough. As many are shooting both film and digital then the lens once again becomes a factor to be taken into account. Then again resolution is just factor to be taken into account. Contrast, distortion wide open and closed down, tendency for flare, and speed all are important.
