Quote Originally Posted by neuroanatomist
FF will let you get the most out of an EF lens - butmore isn't always better.

Acknowledged, a crop uses the best part of the lens, and if you're looking for applications where the resulting field of view being narrower is of benefit, and pixel density is a significant bonus, then yes, sometimes, a crop on a lens designed for a full frame body might actually make more sense.


However, Even if you're using the sweet spot of the lens, ona crop body, even that sharpness is diminished, as whatever blur/imperfections there are, will need to be magnified with the rest of the smaller image space to a greater degree. Plus, from an engineering standpoint, with the qualification of exceptions for telephoto applications, an EF-S design can be a lot more cost effective, because you can completely ignore requirements outside of the image circle required for the smaller sensor.


So, I'm not disagreeing with you, in that there are exceptions. The first time I put my 24-105 on a full frame body, I discovered that at 24mm, wide open, the vignetting was painfully dramatic, and barrel distortion was pretty extreme. OTOH, if I stopped down to get equivalent depth of field, and zoomed in to get the sameand angle of view that I had previously got with my crop body, it become a non-issue. So, a Fuji Apples and Navel Oranges kind of thing, I believe.