40mm screw mount adaptation

[gzuiko]

Hi Brian,

Have you ever tried adapting a 40mm screw mount lens to m4/3? The size is rare enough that nobody make adapters for these lenses. I'm assuming the Xenar lens I have is an early Praktiflex lens, but i'm not 100% sure. It's an uncoated f3.5 5cm Xenar. I got it to mount in an M42 adapter with a bunch of teflon tape just to see if it works. I thought about trying to ream out a 39mm-42mm adapter ring I have and try to make it work, but I'm not sure it would be possible. Any thoughts?

Thanks,

Jim

 

[Roger Hicks]

Try www.srb-griturn.com. As well as 'off the shelf', they make stuff to order.

Cheers,

R.

 

[gzuiko]

Roger, thank you so much for this information!

Jim

 

[Sonnar Brian]

I have not done any adaptations to u43 yet. So many adapters are available, it is amazing.

If the optics module comes out of the mount, I've hacked them into FSU focus mounts. I've done this on 50mm lenses, so the RF coupling is retained. For u43, the latter is unimportant. So- it might be possible to hack the Xenar onto an I-61 focus mount, or J-8. It should be possible to collimate it so the RF coupling is good. It will then work with a 39mm adapter for u43. Can you post a picture of the lens?

 

[gzuiko]

Hi Brian,

Here are some pictures of the lens. There is nothing particularly special about the lens, by the way, in fact, the front element is hazy around the edges. I got it for next to nothing and just wanted to play with it on my Lumix G1. I could be happy adapting it to M42 or any other mount I could adapt to M4/3. The test shots I took with it look pretty low contrast and that's to be expected I guess.

I just like old heavy lenses like this, particularly Schneider lenses.

I unscrewed the front unit in the last shot because it all comes right out.

 

[Sonnar Brian]

It has plenty of back-focus to clear the mirror.

I would be trying the retaining rings on the back of the lens to see if the optics module, aperture and all, will separate from the focus mount. At that point- transplant into an I61 mount.

 

[gzuiko]

Thanks Brian,

Mirror is not a concern since I'm using it with micro four thirds. I'll tinker with it and figure something out. My Xenar lust may have to be fed with a different lens. I knew it was an oddball mount when I got it. It's still a cool old lens even if I just keep it to look at. Will figure out a way to use it somehow though, eventually. Exakta mount, LTM and M42 will all work for me with M4/3. Once I can adapt to one of those I'll be in business.

I appreciate you taking the time to look and comment.

Jim