| Author |
Message |
    
Guido Schattka
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 16, 2005 - 12:46 pm: | 
|
I have an old Tele-Xenar 5.5/180mm Scheider lens with an ugly discoloration in its rear element.
The previous owner obviously already tried to open it (scratches next to the holes).
I am not able to get it apart, I did already drill two new holes into its thread to get more power to my turning motion - but nothing moves. I can't even see a separation between the two parts of the housing. (Are there two parts?) Has the lens-combination been pressed into the "tube"? Is there a different possibility to open it? I have no more idea. Here are some pictures of the patient:
http://jpg.250kb.de/f5320850c89a157f74f1ea51a063f9f7.jpg
http://jpg.250kb.de/2a92bc614c8bd6422cdfe17ed67a07f0.jpg
http://jpg.250kb.de/c29daacaa4fbecf6c9aff22e87e5d89d.jpg
Has anybody done it before, or does anybody know how to open it? Please help me.
Thanks, Guido |
Ed
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 17, 2005 - 02:49 pm: |
|
It should like the ring maybe cemented in place--tried dribbling a small amount of solvent--you may have to add more and see if it will move--I guess I would with lacquer thinner or maybe acetone. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, June 17, 2005 - 04:56 pm: |
|
I assume the whole mount unscrewed anti-clockwise.Silly question but have you tried turning the threaded part clockwise to unscrew it?The use of left and right hand threads is the only way the rear assembly will stay 'whole'whilst being removed from the lens proper.
However it is quite likely that the threaded inner tube is a press fit into the outer or possibly an inner retaining ring used,if mount tube is one piece.Quite a few early lenses used press or rolled over edge methods of retaining lens elements,eg Leitz f2 Summar.In early optics I have only ever found cement used to hold glass elements in place, prior to rolling the edge of the mount or pressing in a retaining ring.This type of cement requires heating to 200 deg C to allow removal of the glass elements.
The disassembly may also require the rolled edge to be removed in a lathe or the construction of a device akin to a miniature bearing puller.I know as I have had to do both in order to resurrect old optics.
Is the lens in question subject to a patent?I have found quite detailed information on construction in some optical patents.Good luck in your quest. |
Guido Schattka
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 18, 2005 - 02:11 pm: |
|
After repeated inspections I tend to agree with Glenn - there is an edge bent over the inner lens-element. I have to ask a frient with a lathe to remove it.
When everything is clean and cemented again I will simply glue it back with epoxy, seems to be the easiest way to me.
Being from Germany I would finally have the opportunity to talk to someone at Schneider-Kreuznach to give me a hint.
Thanks anyway for your suggestions.
Guido |
