From what I've heard, one of the films with the highest resolution nowadays is the Adox CMS 20. Black & white obviously, and to obtain ISO 20, it needs to be developed in a special developer (Adotech CMS). With standard developers (like HC 110) it's only 6 ASA.
Anyway, Fotoimpex in Berlin claims 800 L/mm with high contrast (I never remember if these numbers are good or bad, but I think 800 is supposed to be good
). I've been meaning to try it for some time, but ordering from Germany is such a hassle, and customs in this country is famous for their way of making things expensive when they arrive across the border.
I've seen some samples, and they look good. Only available in 35mm though, at least the last time I checked.
Now Jono, can your Walkman shoot at ISO 20? (Reminds me of the athlete who was asked: "How wide can you jump?". He was Swedish of course
Any Swedes here?).
Found a sample:
Crop:
They claim the image it's a bit blurry because it was taken handheld and because the film outresolves the LEICA ASPH 1,4/50mm that was used.
Correction: CMS 20 is now also available as 4x5. Now, that sounds like a lot of megapixels