martinjames
Established
If you extend the lens, then 'back the bayonet up' and wrap something rubber round the front ring you should be able to shift it but remember that you will need to exert the same force to get it back to its original position.
But then again, if the lens is hazy it is most likely not here, more likely around the iris.
Thanks again for your advice. What I don't understand is how you are able to unscrew just the front piece without taking the connected cell with it. I can take the connected pair out quite easily. But separating the two is quite another thing, it appears!