Mostly if it is sharp wide open. Most fast glass I've used in the 50mm range is somewhat compromised wide open which I understand can sometimes be unavoidable. Although my 135L is stellar even at f/2... so basically how it performs wide open.
Originally Posted by rich815
Also bokeh (there I said it) characteristics. Does it exhibit any nervousness if the bg is extra cluttered?
Just asking opinions although I didn't think anyone would malign it.
Only CY lens I own at the moment is the 50 1.4 planar.