John Navas wrote in
:


If we assume a top (not cheap) non-zoom telephoto lens will resolve 80
LPM (check the MTF charts for your lens), then the maximum resolution
of the lens on a Canon APS-C sensor of 22.3 mm x 14.9 mm (like the 7D)
is 22.3 x 80 x 2 x 14.9 x 80 x 2 = 8.5 MP, far less than the 18 MP
spec of the 7D, and anything more is wasted.

Aliased imaging ... shift everything 1/2 pixel horizontally and vertically,
and what do you get? Gray nothing.

It takes *SIX* pixels, exclusive, to properly sample a line pair.

And there is usable contrast at much higher than 80 LP/mm with a lens like
the 400mm f/5.6, especially if the noise is low and you can sharpen
aggressively.