The Canon Serenar 85mm f2 lens has a Leica screw mount, so it is connected with a 39 - m4/3 adapter. The lens does not lock on the adapter, so focusing can cause it to unscrew if not careful.

The focus action on the lens should not be so stiff as to cause it to unscrew. If it is that stuff, a Lube job is probably required. I use this lens on my M8 with an LTM to M-Mount adapter. I "cheated" and worked a little sewing machine oil into mine. When received, it was very stiff.

Yeah I had to work on my jupiter to avoid it unscrewing from the adapter when focusing. Its fine now.
Mac you got a pic/link to the serenar Canon? It must be from the Canon rangefinders right?

The lens was left alone for several years, I think, so a "lube job" might be appropriate here, too. I have never lubricated a lens, could you give me an idea of how to do so? And, is sewing machine oil like shredder oil or like 3-in-1 oil?

Ulfric,

Here are a couple of pictures of the lens.

Sering machine oil is light, maybe a little more refined than shredder oil. Look in the back of the focus mount, with the camera at closest focus. Seems to me a couple of drops of oil into the mechanism at that point could be worked in while moving from 3ft to infinity.

I checked mine- and that is how I worked the oil in. Set the lens to min focus, look at the rear. There is a cut-out section that exposed the back of the helical. Drop some oil a little at a time and then work the mechanism.

I will get some oil and try it out. The mechanism seems to be loosening a bit anyway, but that would help. I think I need to experiment with some other adapted lenses, because I like the manual focus and quality of this one, especially for stationary objects (relatively, these blow in the breeze a lot).