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Sansfin
Tinkerer
Username: Sansfin
Post Number: 1
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 30, 2010 - 09:26 pm: | 
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I was given a super-tak 50/1.4. The rear element is opague around the edge. The image at wide open seems affected.
The rear element group can be unscrewed quite easily. But I dont know how to disassemble the rear lens group. It's quite stiff. I couldn't find information regarding the rear lens group on the net. I was informed that it could be lens separation of the cemented lenses.
Should i take the risk to clean it? (as it has little effect stopped down) I am afraid that it would go worse. I have no experience in un/re-cementing lenses.
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Gez
Tinkerer
Username: Gez
Post Number: 221
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 31, 2010 - 10:37 am: |
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I'm guessing that the Tak 50/1.4 is a 7/6 configuration with the rear cell composed of a cemented doublet facing the aperture blades and 2 other elements to the back. If looking through the lens with oblique light you see a rainbow effect then the doublet is probably separating, if not, it just may be dirt. |
Don
Tinkerer
Username: Don
Post Number: 55
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 02, 2010 - 04:27 pm: |
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Could be the typical yellowing that happens w/this lens. Try exposing the element to sunlight for a few days. |
Sansfin
Tinkerer
Username: Sansfin
Post Number: 2
Registered: 07-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 03, 2010 - 09:10 am: |
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I put it under the sun for a few days. The yellowing faded a bit. But the "dirt" on the edges are not gone. It seems there's no rainbow under oblique light so I will try to clean it.
Should I unscrew the ring facing the blades, or unscrew the larger ring connected to black barrel? (anticlockwise?) They both seem stiff and I feel I'm going to break it. |
