Jim, I have heard quite a few people say that. The brochure says it will cover 1620 at F22, I found only a hint of dark corner when wide open but when stopped down to F22, it is more than enough. This has become one of my most favorite lenses for 1620. I have two, the AM with a factory shutter seems to have a bit more corner, a black barrel one has almost no corner, I don't know, would a shutter sometimes cause coverage problem?
Tuant
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