Other than the $275, how big a difference is there between these two lenses? I've never had a prime, is the .4 really that much difference in the fixed 50mm lenses. Is there a huge difference in build quality?
http://www.bhphotovideo.com/c/produc...0mm_f_1_8.html
http://www.bhphotovideo.com/c/produc...Autofocus.html