I've researched extensively on the Sigma 50mm 1.4 and the Canon 50mm 1.4, and most people seem to prefer the Sigma with the caveat that it may need to be micro adjusted. This is an issue for me since I shoot with a 5D classic which doesn't have the option for that. I don't have the ability to go in and shoot with several different Sigmas to see if I can get one that doesn't need to be adjusted. So my question is this. Is it worth taking a chance buying one and hoping it doesn't need adjusting, or should I just get the Canon? I'll attempt to purchase used either way. Any help or opinions are appreciated.