Have to be honest that sharpness wide open is pretty irrelevant to me. Character is far more important. I\'m not using f1.2 to shoot sharp. By 2.8 I want sharpness though. Had a look, current lenses on ebay, the non modified with clean glass is at least $600. How do I tell if it\'s radioactive or not? Not that I\'m sure it\'s worth bothering. My Tak does everything I want except focus the correct way. If I was able to standardise my lens collection on a single mount, the fd, it would be worth investing (though not as far as investing into the 50L FD) however if I\'m going to gain size and added adaptors, might as well stick with what I have and love?