Beseler Dual-Mode Slide Duplicator dilemma

I'm not sure if this should be in the MACRO category, or the 35mm category, or the enlarging category -- so I'll start here.

I've got a Beseler Dual-Mode Slide Duplicator. Works great, but I've either got a problem with the Duplicator or a problem with certain lenses. It comes down to compatibility.

Like many slide duplicators, the Beseler Dual-Mode Slide Duplicator comes with a bellows (0-240mm extension) that has removable t-mounts on each end. It comes supplied with a M39-to-T-mount adapter for the front end -- because it is designed to use enlarging lenses for copying.

I haven't had any problem up until now with any enlarging lenses. But I have a Fujinon 75mm and 90mm enlarging lenses that don't have a long enough rear thread to make contact with the thread on the Beseler M39-to-T-mount adapter. I've compared the length of the Fujinon lenses' threads to my other enlarging lenses, and the threads are just a little shorter. They work fine on regular lens boards with a lock ring -- but not with this Beseler M39-to-T-mount adapter.

The Beseler M39-to-T-mount adapter is in perfect shape -- as are the threads on the Fuji lenses.

Is there a way to add more extension to the thread on these M39 lenses?

I haven't found any other M39-to-T-mount adapters.

This might or might not give a bit of insight into your issue...I have a T-mount lens with a T-to-EOS mount adapter.

• The female threads of the T-to-EOS adapter provides about 6mm of female threads
• The male thread of the T-mount of the lens provides about 4mm of male thread

There are T-mount extension tubes available that might work in your situation.
I have a ChromaPro45.
In order to mount my digital SLR on it, I had to extend the distance from the top platform to the T-mount...the camera's flash stuck out too far forward.
I ended up finding a 15mm (?) T-mount extension tube on the big auction site.
IIRC, I found it under microscope accessories....(?)
Something like that might be what you need.

Thanks, but I don't have a problem with the T-mount side of the adapter. It's the lens side -- and there is plenty of thread. But the TWO Fuji enlarging lenses don't have a long enough 39mm thread to reach the 39mm threads of the adapter. All my other enlarging lenses do. At first, I thought I had a "bad" Fuji lens, but my OTHER Fuji lens won't connect either -- although they both have enough thread to fit on a lensboard.

So getting an extension on the T-mount side won't help.

I have looked at SHORT M39 extension tubes, but they all look like they have short threads -- but I have not measured the length. 6mm vs 4mm might make all the difference.

I may be wrong, but aren't T-mount thread 42×0.75 mm? Does this website have anything you can use?
https://customphototools.com/enlarger-lens-adapters/

I have bought a couple of adapters from him, and they were well made. Took a little while to get them from Portugal to USA, but I think worth the wait.

EDIT:
"M39 LTM mount adapter ·Available with M42 mount or T2 mount
Available in aluminum or brass.
For enlarger lenses with 39mm LTM mount thread.
Adapter with female M39 Leica Thread Mount on front. Available with male M42 (42mm x 1) thread mount or T2 (42mm x 0.75) thread mount."

xkaes said:

Thanks, but I don't have a problem with the T-mount side of the adapter. It's the lens side -- and there is plenty of thread. But the TWO Fuji enlarging lenses don't have a long enough 39mm thread to reach the 39mm threads of the adapter. All my other enlarging lenses do. At first, I thought I had a "bad" Fuji lens, but my OTHER Fuji lens won't connect either -- although they both have enough thread to fit on a lensboard.

So getting an extension on the T-mount side won't help.

I have looked at SHORT M39 extension tubes, but they all look like they have short threads -- but I have not measured the length. 6mm vs 4mm might make all the difference.

Click to expand...

So if you measure thread length on the enlarging lenses that work fine vs. the Fuji problematic lenses, what difference is there?!

runswithsizzers said:

I may be wrong, but aren't T-mount thread 42×0.75 mm? Does this website have anything you can use?
https://customphototools.com/enlarger-lens-adapters/

Click to expand...

Thanks. That's exactly what the Beseler Duplicator uses -- except it is black. The problem is the rear threads on the Fuji lenses are a millimeter or two too short, and won't reach the threads of the adapter. BUT this Portuguese adapter might be different enough to make the difference. I'll check it out.

xkaes said:

Thanks. That's exactly what the Beseler Duplicator uses -- except it is black. The problem is the rear threads on the Fuji lenses are a millimeter or two too short, and won't reach the threads of the adapter. BUT this Portuguese adapter might be different enough to make the difference. I'll check it out.

Click to expand...

If his stock thread converter does not have longer threads, that seller is a machinist and I believe can make a custom adapter to your specifications.

Problem solved. I found a L39-to-T-mount adapter (and a T-mount-to-L39 adapter) -- for free.

The L39-to-T-mount adapter is the one I needed. It's exactly the same as the Beseler model, except that it is about two millimeters thicker and the L39 threads are about 2mm closer to the end. That's just enough for my Fuji lenses to catch.

It's unbranded except marked "Japan".

And I can use my original Beseler adapter with other L39 lenses, so changing lenses is a bit easier.

And with my other T-mount-to-L39 adapter, I can put my T-mount lenses on my L39 camera -- should I ever acquire one -- or on an enlarger lenses board!??!?