Roger Cicala has written a cogent — and sobering — blog post on lens testing and copy variation.
I think it’s a must read for those of us who test lenses, and something anyone who uses lenses and examines the results critically could get a lot out of.
Great article indeed. I remember a few years ago, as Nikon gave the D800 to Zeiss with the order to make a lens FOR this digicam! Result Otus was born! That is it.