My glass-pushing friend Jimmy loaned me a Pentacor 135mm f2.8 compact lens a while back. It’s in the Practika B mount, which is a bayonet. I didn’t have an adapter for my NEX, so I had to wait for one to be shipped from China.
The adapter arrived late last week, so I put the lens on my NEX the other morning for walkies. The image quality is quite good. The colors seem a little cool (probably the Zeiss heritage), but the lens is adequately sharp wide open and has a very well behaved bokeh. The out of focus background is smooth and not busy. I rather like the lens.
If I didn’t already have so many 135mm lenses, I’d probably keep it. If the price is right, I’ll probably keep it anyway. 🙂