Mounting a J-12

[dazedgonebye]

I know it should be simple, but try as I might, I can't get my new J-12 to screw on to either the fed-2 or zorki-6.
I just can't get the threads to catch.
If feels like the rangefinder arm keeps the lens from getting in the right position.

Any trick here, or do I just need to persevere beyond the 30 minutes I've given this so far?

[brachal]

I remember a thread or 2 where people have had issues with the rangefinder arm preventing the threads from engaging on a 12. The solution, IIRC, is to bend the rangefinder arm up slightly.

I've never tried this, so proceed with caution.

[fidget]

Yes, this is what i had to do on two cams. It only had to move a fraction of a mm upwards, so do it gently. I recall that this was common.

[dazedgonebye]

I'll give it a try.

[rbiemer]

Steve,
With my J-12 and FED5, I set the lens focus so that the focus helical and mounting threads are even. Then as I gently start to mount the lens, the rf cam is moved out of the way of the mounting threads.
With my camera the force of the rf cam is enough to slightly angle the lens and make mounting difficult.
Rob

[dazedgonebye]

I finally talked the lens on to each camera, but it is so tight and ill fitted that I can't focus it without unscrewing it from the mount.

Such a pretty little lens, and me with 2 FSUs and no way to use it.

[payasam]

I had to press the R/F coupler of my Zorki 1 upwards with a thumb before my J-12 would fit. When mounting or unmounting a lens, it should be set to closest focus.

[wolves3012]

The FED 2 has a known and common issue with the RF sensor, just bend it upwards a tiny fraction if needed - take the back off and have a look first to see if that's the issue. As payasam says, always set a lens to closest focus before mounting, it moves the lens cam as far out of the way as possible. I can mount the J-12 on any of my FSUs without a problem so check your technique first.