thisistheverge:

Buying a Used Lens—How To Win

An amazing guide from our forums:

Your testing will take hours, the seller will tap his/her foot impatiently and probably end up storming out in a rage. I guess what I’m saying about used lenses, if I’m saying anything, is that you should know all the features and specs but you shouldn’t expect the same result as what DxOMark publishes. You should expect some margin of error, which means you don’t have to do super precise testing. Having said that, I’m now going to detail the things I do when I test a lens.