Photoclubalpha

Has anyone used one of these? Can they be used as ordinary adapters with a zero degree tilt? The Hongkong sellers describe the need to rotate the ring away from the 180 degree position but I have no idea what that means.

That's just the locking ring. If you want one for M42 I am happy to sell you one for less than whatever the current Hong Kong price is. They can easily be used 'straight' and they lock really firmly - using the two lugs to clamp the pressure ring, by rotating the collar.

David

Thanks, David for clearing that up. But I have no M42 lenses I'm afraid - considering getting one for a wide angled Olympus OM.

I purchased an M42 model and it looked good, but had the wrong thread. It took me ages to persuade the supplier that I had a regularly used M42 adapter and did know what I was talking about. Eventually the supplier came back and confirmed that his entire stock marked M42 was the wrong thread. Just warning in case you find a stock of cheap ones