Repairing Reichert objectives

[Xavier]

Hello,

If you don't mind I have another question about Reichert.  This time about repairing Reichert objectives.
Several of the transmitted objectives have black spots.  If you look through them you see them clearly and it's very hard to focus.
If I examine the lenses with a magnifying glass I don't see them.  Tried to clean the objectives without success.

With some of the EPI objectives there is another problem.  Not with one objective but with several objectives.
The surface of the front lens isn't clear.  It's like frosted glass.
You can see it clearly with a magnifying glass.  Again tried to clean it.  But no luck.

Has anyone similar experiences with objectives? 
Can it be solved?

Thank you very much.

Xavier

PS: Answers in German are no problem.

[JB]

If you don't mind I have another question about Reichert.  This time about repairing Reichert objectives.
Several of the transmitted objectives have black spots.  If you look through them you see them clearly and it's very hard to focus.
If I examine the lenses with a magnifying glass I don't see them.  Tried to clean the objectives without success.

Hi Xavier,

What is the size of the black spots and how many are there?

I have two Leitz objectives that also have black flakes on the internal lenses. They seem to originate from the black paint inside the objective. As long as there are only a few, it makes no difference to the image quality.

All you can do is to carefully clean the front lens and the rear lens.

It is NOT possible to open objectives to clean the inside, because the lens segments are carefully calibrated by the manufacturer. When you take it apart, you lose the calibration irreparably and the image quality will be much worse. So you will have to live with it and the current condition!

Quote: "When the objective is assembled, spherical aberration is corrected by selecting the best set of spacers to fit between the hemispherical and meniscus lens (the lower lens mounts). The objective is parfocalized by translating the entire lens cluster upward or downward within the sleeve with locking nuts so that focus will not be lost while objectives housed on a multiple nosepiece are interchanged. Adjustment for coma is accomplished with three centering screws that optimize the position of internal lens groups with respect to the optical axis of the objective."
http://zeiss-campus.magnet.fsu.edu/articles/basics/objectives.html

Kind regards, Jon

[Klaus Herrmann]

Hallo Xavier,

The surface of the front lens isn't clear.  It's like frosted glass.

Forgett it! Es gibt wenig Hoffnung. Das Problem wurde vor einiger Zeit hier diskutiert ich denke von Franz.

[Xavier]

Thank you, Jon and Klaus,
You have the answers I was afraid of. 
Luckily not all the Reichert objectives are affected.

@Jon: the black spots in some of the objectives are so important that it isn't possible to observe.  About 2/3 of the image is covered.
Can certainly not use them for photography.
It are objectives from the 1950's and 1960's.

Time to replace them.
Any suggestions?  The tube length is 160

Best regards

Xavier

[JB]

@Jon: the black spots in some of the objectives are so important that it isn't possible to observe.  About 2/3 of the image is covered.

Hi,

Can you show us an image of the black spots? I can't imagine what that would look like.

[Xavier]

Will make one.  Don't have a photo of the black spots.