"Why would you want to do such a thing?", you may ask. Simple. This legacy lens is solidly built, has superb optics (even when wide open), and does not cost an arm and a leg. I've had the pleasure of shooting with the Canon EF 50mm f/1.2L USM — the lens exhibits marshmallow-like sharpness wide open, and the ultrasonic motor leaves much to be desired (it's REALLY slow for a USM). So, I decided to look for an alternative lens within the same focal range.