Tele-Xenar 360/5.5: strange thread on front element

[Andrey Vorobyov]

Hello everybody!
I've recently bought the Tele-Xenar 360/5.5 without shutter and tried to mount it into Compur #3. The back element fits nicely (the standard 58mm thread with step 0.75) but the front element has smaller thread: something between 55 and 56mm and I'm completely not sure about the step.

Schneider catalog 1939 mentions the unknown to me shutter "III/7":
http://www.cameraeccentric.com/img/i...eider_2_28.jpg
I suppose it is Compound shutter rather than Copal/Compur.
Is my guess correct?

Can anyone tell me exact size/stepping of that front thread?
I have suspects that the thread is even not metric...

I think it is possible to make a ring-adapter between the standard 58/0.75 and this strange thread. But may be such rings are standard and already available commercially?

Thanks!
Andrey

[Peter K]

I've recently bought the Tele-Xenar 360/5.5 without shutter and tried to mount it into Compur #3. The back element fits nicely (the standard 58mm thread with step 0.75) but the front element has smaller thread: something between 55 and 56mm and I'm completely not sure about the step.

Are you shure its not a Copal #3s with the M 56 x 0.75 mm thread?

I suppose it is Compound shutter rather than Copal/Compur.
Is my guess correct?

The Tele-Xenar 360 with the conical front barrel was aviable either mounted in Compound #III 7 or Compur #3

The Compound has as you can see here a 55.69 thread.

The Tele-Xenar 360 with the cylindrical front barrel has threads for Compur #3 and Copal #3 - not #3s! - shutters.

Peter

[Andrey Vorobyov]

Are you shure its not a Copal #3s with the M 56 x 0.75 mm thread?

No, Peter, I'm not sure. I'll try to measure more precisely this evening.

My lens is with the conical front barrel. Tiny inscription "Linhof". The rim (ca 1 cm) of the very front is in chrome. I can post photos tomorrow.

Thank you for the link with sizes!
For now I'm inclined to think is that the thread diameter is indeed 55.69mm so the dedicated shutter was compound 3, but let me measure more precisely..

[Ole Tjugen]

Nice to see my post being referenced to.

Note that all Compounds have identical front and rear threads - so if your lens has different threads, it's not foe a Compound shutter.

To compound the conundrum, there were Compur shouuets produced with the same threads as the Compurs in a short transition period.

[David Lindquist]

Nice to see my post being referenced to.

Note that all Compounds have identical front and rear threads - so if your lens has different threads, it's not foe a Compound shutter.

To compound the conundrum, there were Compur shouuets produced with the same threads as the Compurs in a short transition period.

For some time now I've been meaning to thank you for the Compound shutter dimensions, Ole.

Now do you have any idea how and why they came up with a pitch of 29 1/13 threads per inch for the flange thread???

And in your last sentence did you mean to say there were some Compur shutters produced with the same threads as the Compounds in a short transition period?
David

[Andrey Vorobyov]

Front element thread outer diameter: 55.6 +/- 0.1. Cannot measure more precisely.
I visited a friend who has Compound shutter and we tried to mount my lens. Now the front element fits ok, but the back element is too large!

Good news is that I was able to find and borrow the ring 55.6->58 that allows my lens to be mount into standard Compur #3. The machining quality of the ring is very high, I believe it was made in a factory. I hope I can order a clone by a local machinist, so from practical point of view there are good chances to solve the problem.

Note that all Compounds have identical front and rear threads - so if your lens has different threads, it's not foe a Compound shutter.

Ole, then it is a puzzle what shutter my lens was dedicated at production time!

By the way the serial# is 13,213,731 so according the page
http://www.schneider-kreuznach.com/service/serie.htm
this lens has been made between September 77 and October 78.

[Ole Tjugen]

Now do you have any idea how and why they came up with a pitch of 29 1/13 threads per inch for the flange thread???

Yes, it's a result of the slope of the cut of the threads. I think they used a 50 degree angle instead of the more common 60 degrees, giving a really strange threadcount.

And in your last sentence did you mean to say there were some Compur shutters produced with the same threads as the Compounds in a short transition period?
David

Yes. Apologies for the misspellings...

[Peter K]

By the way the serial# is 13,213,731 so according the page
http://www.schneider-kreuznach.com/service/serie.htm
this lens has been made between September 77 and October 78.

The production of Compound shutters was ceased nearly ten years earlier.