Film resolution (Score 1)

A real good film (e.g. Fuji Velvia) can distinguish 160 lines pairs / mm. That means 2 alternating black and white lines, thus you need 320 pixels/mm. Given the size of a 35mm is 24x36 mm^2(NOT 35), you get 320*24*320*36 = 84 MPixels.

Eat that.

Note that no 35mm lenses can't reach 160 lp/mm, most pro lenses can reach 100. If you have 20/20 vision you can do about 5 lp/mm. Having said that' I'll give my right (20/22) eye for a EOS1Ds.... See http://www.photo.net/bboard/q-and-a-fetch-msg?msg_ id=001SWX for a somewhat aged, but photographically accurate analysis of film vs digital.