[stoppingdown]

I look at the MTF chart, that shows a dive at the extremes. Is that not consistent with the images? So my interpretation of this is that it is not a QC problem but the actual design was never going to give you decent borders in the first place.

 

My comprehension of MTF chart is not strong, but I was thinking the same. Which would be a pity, of course. But - I've seen some full-res photos that have better resolution in the corners than the tests published by Kurt. That's why I'm still dubious. I mean: one thing is reckoning that corners are much worse than the center as the charts suggest; another is understanding in visual terms how this loss of quality looks.