So can anyone tell me when you put a lens that is designed for a full frame camera on a crop sensor body like the Canon T2i is the entire glass is being used?
I got this answer from titaniumslug on YouTube which sounds like the correct answer:
It does only use the centre of full frame glass. This has the advantage that light fall off (vignetting) & softness in the corners at large apertures will be cut off. However overall sharpness (in stills only) will be less on a crop sensor. If the two cameras have the same number megapixels then the crop sensor will have smaller pixels which means it has a smaller area of the glass to deliver sharpness for each pixel. This is why on the dpreview tests the same lens scores higher on full frame.
Royalty free music by PremiumBeat.com
Products Used In This Video
Help me make more of these types of videos by purchasing gear from the links posted on my site. It costs you nothing extra, and helps support me to make more videos.