Sonnar 135mm f4-what mount?

[bogdanb]

I picked up this Carl Zeis Jena Sonnar 135mm f4 for cheap a few days ago, but I'm having troubles determining what mount is in. It looks like a M39 and I can screw it in on a LTM camera, but it won't action the rangefinder (the inner ring that usually pushes the cam follower is too far recessed into the lens, and it won't get anywhere beyond the point where the outer threaded ring ends, as you can see in the picture below). Is it a m39 lens made for Zenit SLRs?

 

[GaryLH]

I found this when I googled "Zeiss ltm lens"

http://www.dpreview.com/forums/post/31490682

http://www.rangefinderforum.com/forums/archive/index.php/t-126759.html

http://www.mflenses.com/how-to-avoid-zeiss-sonnar-fakes.html


Gary

 

[bogdanb]

It definitely doesn't have the contax mount. The sn is 4905###, which puts it in the late 50's, according to the lists one can find on the internet. It doesn't look like any of the jupiter 11 variants listed here.

http://www.sovietcams.com/index.php?173991321

It actually looks very much like many 135mm f4 sonnars made for exakta, but it doesn't have a bayonet mount.

 

[tunalegs]

Paxettes used an m39 thread mount but with a longer register than LTM.

 

[LeicaTom]

Looks like a modified M42 lens made for some sort of extension tube, its NOT a Leica LTM lens......

Tom

 

[GaryLH]

Could it have been a lens converted to be used for visioflex?

Gary

 

[bogdanb]

Looks like a modified M42 lens

Tom

That's what crossed my mind too. Is it possible to machine down a m42 mount to a m39?

 

[tunalegs]

That's what crossed my mind too. Is it possible to machine down a m42 mount to a m39?

How is the aperture operated? Is it a preset lens? Does the aperture "lock" into place? Or is it a manual (aperture) lens?

By the late 50s, I don't think Zeiss was making manual diaphragm lenses for SLRs. If it has a preset diaphragm (lift and set) then it is definitely an SLR lens.

 

[bogdanb]

It doesn't have an aperture pin. As it is now, the only way to stop down the lens is by using its aperture ring, although there are 2 small holes at 3 and 9 o'clock that could have accommodated some sort of pin (see the photo below).

 

[sevo]

Sure that that is no internal thread, on a lens that lost its (presumably Exakta or M42) mount? One of the holes might be the counterpart to the locking screw that once secured the mount, the other could have housed the plunger for the auto aperture.

How long is the lens, at infinity?

 

[bogdanb]

How long is the lens, at infinity?

9cm, from where the filter ring starts to where the mount/"mount" ends.

 

[chrishayton]

It's exakta, some early exaktas had a 39.5 screw fit.

 

[tunalegs]

It would not be a semi-auto lens (fully automatic diaphragm operation was not used on the aluminum barrel CZJ lenses so far as I know).

But if it is a preset lens you have to push the aperture ring in then turn it to the desired f-stop. The diaphragm operates the same as on a manual lens, but it won't stop down further than the selected f-stop. That's a preset lens.

Compare to this one that sold on ebay: http://www.ebay.com/itm/112-CARL-ZE...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

 

[sevo]

9cm, from where the filter ring starts to where the mount/"mount" ends.

Not a Exakta mount gone missing, then. My 60s "zebra" 135/4 for Exakta is 76mm from flange to front element. As the thread must end inside the flange to leave enough metal for the mount, it could only be Exakta (or M42 - the dimensions are similar) if the front element should be recessed by something upward of 15mm behind the filter ring (which would be unusual enough that you'd probably have mentioned it).

So back to start - manual aperture, body too short for rangefinders, and too long to have lost its original SLR mount. Might be missing its original rangefinder (if so, presumably Contax) mount, or could be a custom conversion to Zenit M39 (exact measures would be needed to verify that) - or some bellows/macro ring/visoflex thing, whether factory made or converted.

 

[sevo]

It's exakta, some early exaktas had a 39.5 screw fit.

But did CZJ build lenses for rare pre-war Exaktas in the late fifties?

 

[bogdanb]

But if it is a preset lens you have to push the aperture ring in then turn it to the desired f-stop. The diaphragm operates the same as on a manual lens, but it won't stop down further than the selected f-stop. That's a preset lens.

Compare to this one that sold on ebay: http://www.ebay.com/itm/112-CARL-ZE...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

yes, it is a preset lens. thank you for the explanation 😉. never played with one before

 

[zuiko85]

Could it be for one of those early Russian SLR's that used the 39mm mount size but at a different register distance. One test that could be done is to position a ground glass behind the lens and see how far from the thread seat it brings an object a couple of blocks away into focus. For LTM rangefinder it should be about 28.8mm if I remember right.

 

[bogdanb]

Not a Exakta mount gone missing, then. My 60s "zebra" 135/4 for Exakta is 76mm from flange to front element. As the thread must end inside the flange to leave enough metal for the mount, it could only be Exakta (or M42 - the dimensions are similar) if the front element should be recessed by something upward of 15mm behind the filter ring (which would be unusual enough that you'd probably have mentioned it).

So back to start - manual aperture, body too short for rangefinders, and too long to have lost its original SLR mount. Might be missing its original rangefinder (if so, presumably Contax) mount, or could be a custom conversion to Zenit M39 (exact measures would be needed to verify that) - or some bellows/macro ring/visoflex thing, whether factory made or converted.

The front element is recessed by ~9mm with respect to the outer end of the filter ring.

The lens was part of a deal with an enlarger, so it might have been used at some point in time as an enlarging lens, although I fail to see the point of doing that.

 

[sevo]

yes, it is a preset lens. thank you for the explanation 😉. never played with one before

Ok, that makes it a product intended for some sort of SLR use, whether for Zenit ZM39 (can't find any reference to CZJ making lenses for it, but socialism sometimes generated semi-official off-plan products), or a bellows head. Or, of course, some more severe custom modification from one of the regular GDR SLR mounts, involving a barrel replacement (or perhaps, cutting a M39 thread on top of a pre-existing M42).

 

[bogdanb]

Could it be for one of those early Russian SLR's that used the 39mm mount size but at a different register distance. One test that could be done is to position a ground glass behind the lens and see how far from the thread seat it brings an object a couple of blocks away into focus. For LTM rangefinder it should be about 28.8mm if I remember right.

I have just measured the flange distance that way and it seems to be 35mm or so, but I'm not sure how precise I was.

EDIT: remeasured it and it is more like 42mm