There is one thing in this review that I don´t quite get and that is the vignetting. I did not do a real vignetting test before, I just looked at drop-off when I had a large area going to the edges of an even blue sky or evenly lit snow etc. and I concluded that it was very good. But having read this review and the conclusion that vignetting was actually quite bad, I had to be a bit more thorough, so I took a white cardboard, lit it evenly and shot 1.4, 2.0, 2.8 and 4.0 and what I see is different to what lenstip reports. I have (much) less vignetting than they report. My 1.4 result is quite close to their 2.0 and at 4.0 the problem is gone. To me this is a bit confusing. I always thought vignetting would be very stable from lens to lens. Have anyone experienced the same on this or other lenses?