Hi,

In terms of getting the maximum power together with the maximum usable
details and sharpness from a particular telelens, I wonder which option
gives the best results for a particular purpose: let's say: get the max.
amount of details of a bird on a 1600x1200 display.

A full frame SLR (EOS 5D 12 megapixels) combined with a top class CANON
400mm

or

a EOS 20D (crop factor = 1.6x but only 8 megapixels)) combined with the same
lens as above


From a general point of view and at equal sensor resoultion, does a smaller
CMOS provide any advantage in terms of power and resolving small details if
using the same lens?

Another question:

What will be the best buy for widelife photography: EOS5D with Canon 400mm
or NIKON 200D with Nikon 400mm
10 megapixel + 1.5x or 12 megapixel FF

Thanks for your advising me

Erick