Unknown Schneider Kreuznach Xenon 25/1.4 lens with C mount

[georgios]

Dear all,

I have been following you great forum for a while and decided to post here for the first time.
I recently bought a Schneider Kreuznach Xenon 25/1.4 lens with C mount with the intention to adapt to my M4/3 camera.
However the lens I found on ebay was not a typical C mount camera lens! The bayonet in the rear is C mount (I can screw it to the reverse of the adapter),
but there is a ring that does not allow the lens to go all the way in the adapter! Another strange thing with this lens is that the aperture can close all the way!!
Someone told me that this is probably a lens that was used to develop or magnify negatives.
When I try to take photos holding the lens near the sensor, I get almost full coverage with minimal vignetting.

I am attaching some photos of the lens. Excuse the bad quality but they were taken with my mobile phone because I do not own another camera at the moment.
Any input will be greatly appreciated. I would like to know if I can modify this lens in order to fit the adapter of if there is some other kind of adapter I could use.

Thank you in advance,
George

#1


#2


#3


#4


#5

[guardian]

[georgios]

Thank you Guardian ,

I did think of removing these screws. In fact the black ring is what really causes trouble.
A machinist is a great idea. Does anybody know if I can find one in the Netherlands?

Thank you again,
have a nice weekend!

[kds315*]

A lot old older lenses for video TV cameras allowed the iris to close completely
to prevent the vidicon tubes to burn in.

[georgios]

Thank you Klaus for the clarification.
Indeed, from my research it turns out thatenlargement lenses do not have a focusing ring, which is not the case here.
Therefore this is a really old and rare Schneider cine lens with non-standard C mount (??).

Anyhow, I unscrewed the 6 screws onthe basck side and this is what I got.
Any ideas?

Thanks,
Geogre

#1

[guardian]

Oh, OK.

Your additional photos are helpful. So it is the black ring causing the problem. Then my earlier post was off target. Perhaps you could find a different brand adapter with which the black ring would not interfere? Otherwise I dunno.

It might help to see your adapter since that is what appears to be causing your dilemma. Or possibly the adapter could be machined to facilitate things by relieving the interference.

Looking at your new photos, I no longer think machining of the lens itself would be appropriate.

[georgios]

Thanks a lot of all the help!
@Guardian I am adding some more photos. Looks like that even the nickel ring cannot fit into the adapter's circular area.
When I screw the bayonet on the back side of the adapter as you can see it fits well!
So maybe the adapter is not fit for the job. Does anyone have any suggestions as to what kind of adapter i could buy, or a way to make a #D model
and then have it printed?
Also any info on machining services in the Netherlands will be very much appreciated.


Regards,
George


#1


#2


#3


#4

[kds315*]

Excuse me, but why would you think this c-mount is "non-standard"?
Just because it does not fit "some" modern c-mount adapter?? What's
non standard is the modern adapters, NOT the c-mount! No one had problems
using this lens then....and btw. what is "standard"?? Maybe you want to
read this: https://en.wikipedia.org/wiki/C_mount to understand
what the "c-mount standard" is. A certain flange-focal distance and a
certain special thread mount, that is (was) all making up the c-mount
"standard" .... sorry, I'm a bit sensitive as an engineer and it ticks me off
if a cheap chinese adapter is being used as "the standard" which some well
made lenses have to match to.... 180 degrees wrong

[georgios]

I am sorry Klaus for the wrong wording,
I read the wikipedia page, and I understand that semantics are important in engineering.
So, the correct phrasing would be that this is in fact a standard c mount thread but the base of the lens is too wide to fit in the recess of an adapter made
some decades afterwards. If I had a camera with a standard C mount it would fit.

Regarding the adapter, it was not that cheap (30 Euro) I bought it from a local
store and I hoped it would be better than the ebay Chinese adapters.

Anyways, no need for controversy here, in my enthousiasm trying to use an old glass on a new camera I inverted the logic.

Any help with this task would be appreciated.

thanks

[Eddie46]

Just a thought. Is it possible the silver ring that you have now removed was someones elses earlier adaption .I couldnt help noticing the Outer ring of holes on the rear of the lens itself.

[guardian]

Oh my goodness that seems a great deal of money for a C-mount to m4/3 adapter!!

I own only one such adapter, but I can ASSURE you I paid nowhere near that much money for mine. Of course, as most of us do, I ordered my adapter from China, or Hong Kong, and I had to wait for delivery. Such a wait is routine.

Anyway, take a look at the Chinese adapters. Perhaps you will be able to find one that will work straightaway, or is inexpensive enough to where you can afford to purchase and then modify it.

It's a troubling day when adapters cost as much or more than lenses . . at least many of the ones I buy!

[Ernst Dinkla]