I have had an Opemus 5 for about 2-3months and been getting on fine but only had a Belar 50mm f/4.5 which has been fine enough.

This week I got a 50mm El-Nikkor f/2.8 - the N variant. The lens board is 39mm fitting (not the older 25mm)

I have just tried to screw it in but the actual physical diameter of the lens is too broad to fit into the lens board itself and it won't screw in as it physically can't get close enough. Gnnghhh!

I have tried vainly I know, to flip the lens board over as if I was mounting an 80mm lens but to no avail (surprise!) as even though it screws in this way around, it never attains focus (which you'd expect!)

Does anyone have any ideas apart from me selling this Nikkor lens? I'd really rather not

I'm worried when I get an 80mm lens I will have the same issue as I have my eyes on an EL Nikkor f/5.6 80mm.

Many thanks,