| Author |
Message |
    
Ben
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 29, 2004 - 01:21 pm: | 
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The shutter blades of old M42 mount Jena Tessar 50mm f2.8 lens are stuck wide open. Are there any ways to dissemble the lens from the front to clean the blades? I'd appreciate some help. |
Michael Tan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 05, 2004 - 08:05 am: |
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Try this link to Chris Sherlocks's website for instructions to disassemble a Pentax lens. The principles are more or less the same.
http://homepages.ihug.co.nz/%7ESrawhiti/pentax50mmf1.4.html |
Ben
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 05, 2004 - 06:17 pm: |
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Thank you for your link, Michael. However, I can not remove the the decorative trim ring as I did to other Japanese lenses, no matter how hard I tried. I can't help thinking if the trim ring had been cemented to some point of the lens barrel. Please advise me of more options. |
Jan Dvorak
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 05, 2004 - 06:44 pm: |
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Ben,
You might have checked this already, but are there any tiny set screws that would prevent the trim ring from unscrewing? Sometimes they are only visible when you extend the focusing ring all the way. Sometimes they are also on the lens side (inner filter side).
Which version Tessar is this - silver aluminum mount, or the later black one?
Good luck,
Jan |
Ben
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 05, 2004 - 11:00 pm: |
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Jan,
I have carefully checked to see if there are any tiny screws that secure the trim ring already. There aren't any even when I extend the focusing ring all the way, neither on the inner filter side.
My Tessar is a later black one. It is an aus Jena DDR T 28/50.
I still need more of your advice and help.
Ben |
Gary A. Turner
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 30, 2004 - 09:30 am: |
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I just cleaned the aperture blades on a later Tessar 2.8/50 Carl Zeiss Jena DDR #323291 (M42 lens). That lens was rather easy to disassemble from the front (& rear if you need a more thorough cleaning of elements, etc.).
The front inner barrel on mine screwed out in one unit using a rubber stopper.
On another Tessar variant (the so-called 'Zebra' metal barrelled & ringed lens) the inner filter trim ring unscrews separately. Neither of these 2 lens types have any surface screws in the filter trim rings to remove. In both versions, the inside surfaces of the filter trim ring or inner barrel may have been coated with an adhesive. You can try dabbing naptha around the filter trim ring (on the Zebra type) to help loosen things, then use some appropriate force with a rubber stopper to spin the ring counterclockwise. On the plastic smooth inner focusing barrel variant you can place the stopper on the raised part of the inner barrel. Hope this all makes some sense. If not, please reply. |
