Help me with this lens

[p.giannakis]

Hi guys,
Sorry for the bad picture. This is a Zuiko 50 1.4 i got very cheap. It has a spot of fungus at the rear element.

I am trying to unscrew the retaining ring shown by the arrow but i just managed to hurt my hands instead - it does not unscrew.

Is there something else i should have unscrewed first? Is it just the case that it is stuck? How can i proceed?

Regards,
Pan

 

[Sid836]

Does it affect the quality of the image? If it is a tinny spot kill it with UV and just let it be there.

 

[Jockos]

I think you have to remove that whole cell first.

 

[p.giannakis]

I think you have to remove that whole cell first.

I am under the impression that the retaining ring holds one element to the rest of the group.

 

[Phil_F_NM]

Can you grip the retaining ring holding that last element in with a piece of rubber? Like an old, clean bicycle inner tube? This is what I use on rings that don't take spanners.
You could also take a low temperature soldering iron to the ring at a few points to soften up the thread locking agent in there.

Phil Forrest