I tried this ring with a 35mm MD and MD 50mm 1.7 on the Sony A7 and the focus on infinity is perfect, and also on the edges. Some rings have indeed the tendency to not be perfectly flat and offset observed on one of the edges, this is not the case here. I was lucky? I had previously purchased a Novoflex for another optical brand, I do not see what it brings me more for 15 times more. In the lottery of chinoiserie, I once won. unbeatable value for price and total satisfaction.
