M50 f4 macro on K5

I have just bought on the above lens on a buy it now price which means I can return it for any reason but I suspect it is faulty. I set it to f4 iso 80 on manual and pressed the green button and the speed was 1/5th of a second. At f32 it is still 1/5th second. If I change the iso the speed changes.

John, with the lens not attached to the camera, is the aperture opening and closing when you turn the aperture ring? If so, there's nothing wrong with it, if not, it is faulty.

Regards
David

When you turn the aperture ring nothing happens. It only stops down when you push the lever on the side down and feels sort of sticky. It will not snap back.

It is faulty, send it back. Most likely it has oil on the aperture blades.

Regards
David

Faulty, send it back.

If the return postage is more than the cost. Chalk it up to experience and have a try at stripping and cleaning the insides. It can be done, even with fingers like popeye (mine) if you proceed carefully.

Otherwise send it back as suggested above, would agree with David's analysis.

Bernard