Sorry for the typos... I have just spent a lot of money getting that tendonitis in my fingers partially fixed. But the same comment I made to Sal applies to those
allegedly definitive tests by Perez and KT. They aren't scientifically valid either. Do you REALLY think that kind of casual "batch" testing is more tightly controlled than how modern lens manufacturers with serious engineers and machining equipment define their own quality control ?????????????????? Nonsense.