odd 1930ies COMPUR shutter replacement?

[Dr Klaus Schmitt]

I have a Zeiss Jena lens here mounted in a COMPUR shutter (which I need to
replace) and the sizes of the lenses are strange for me (M36 x 0.75
on front AND rear) - unknown to me! Usually this was for a size I
shutter M40 x 0.75 (front) and M36 x 0.75 (rear) and for a size O
M29.5 x 0.75 (front + rear). The age of my lens is about 1930 I would
say, so which COMPUR type is that and where could I find a
replacement or a barrel I could mount the lens elements into?

Enlighten me please!!

Thanks, Klaus
postmaster@macrolenses.de

[Glenn Thoreson]

If it dates to the '30s, it would have been in an early rim set Compur. Unfortunately, there was no real "standard" for these things. They were usually made to the camera builder's and/or the lens maker's requirements. I sometimes think the phase of the moon entered into the equation, too. Probably the only way you'll find an original style shutter is by trial and error. I think I have a non functional one that might be usable as a mount, but that's about all it would be good for.

[Peter K]

There was a standard for Compur-shutters but it has changed in 1927.

Your shutter is an old Compur I R with the same thread front and rear of 35,7 x 0,635 mm. The mounting thread is 39,0 x 0,875mm, max aperture 27mm, housing diameter 66,0mm and tube lenght 23,5mm. But all this is different from modern shutters.

[Dr Klaus Schmitt]

Thanks guys / Danke Peter (Grüsse nach Nürrrnberrrch)!

That lens seems to be anyway a "rare bird"...

[Steven Tribe]

Another quartz lens for your collection!
Don't worry, the Kalosat wil appear some day!

[Dr Klaus Schmitt]

Hopefully not the last one I will EVER find...LOL

[svlindbe]

Are you shure the shutter is beyond repair? A replacement may not be very easy to find, so a repair seems like a good idea if possible. If the aperture mechanism is good (or could be made functionable) you could always keep the shutter open and use it as a barrel. In what way is the shutter defective? Have you tried to open it to investigate?

Svein Lindberg

[Dr Klaus Schmitt]

The aperture is stuck, the shutter fires. I don't tamper with shutters, they're way too complicated for me.

[Glenn Thoreson]

Klause, when you said "30s", I assumed the shutter would be the rim set version that came out ca. 1930. That shutter is a dial set, which went out of production in 1929. There were, of course, some carry overs. That dial set Compur is one of the most easily repaired and reliable shutters anyone ever built. It's well worth sending in in for a good cleaning.
You wouldn't regret it. I have done simple cleaning on many of these and they continue to serve me well.

[Arne Croell]

There was a standard for Compur-shutters but it has changed in 1927.

Your shutter is an old Compur I R with the same thread front and rear of 35,7 x 0,635 mm. The mounting thread is 39,0 x 0,875mm, max aperture 27mm, housing diameter 66,0mm and tube lenght 23,5mm. But all this is different from modern shutters.

Interesting. I recognize the tube length - the GDR-made Prestor shutter size 1 (made in 1964) also had a 23.5mm tube length, now I know where that number came from. The threads for that one were M40x0.75 front AND back. Peter, does that correspond to another old Compur size?