FWIW, I also tested several different 4x5 lenses when I had my Betterlight scanning back. Here, many of the contemporary pieces of glass equalled the resolution limits of the sensor, about 54 line pairs. Even some old lenses from the early 1930's through the 1950's got very close to that, though many tapped out at around 30 line-pairs. Surprised me actually to discover that as a group, the contemporary large format lenses were that good...
Yes, it is surprising. I still think, though, that the MTF of those 60 lp/mm is critical for real world images. Even cheap 35mm zooms can deliver 60 (and more) high contrast line pairs which are still easily distinguishable even though they might have lost 80 or 90% of their original contrast by the time they are recorded.
What happens if those line pairs are not
high contrast, say medium to low contrast? A camera like the Canon 20D, although its sensor is capable of recording 60 lp/mm, simply wouldn't be able to record them using a cheap zoom. But it probably would when using a good prime, provided the contrast of the target wasn't t too
I would find it difficult to believe, if I were to use my modestly okay Canon 100-400 IS zoom at 400mm and f16 on my 5D, and take a mosaic of around 64 images which, when stitched, would have the same FoV as a single shot with an LF 400mm prime, that the single 8x10" shot at f16 would even be nearly as sharp, assuming you didn't use shift movements.
I could be wrong, though. Would someone care to do the experiment .