| Author |
Message |
    
Taka Iwasaki
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 25, 2004 - 05:39 pm: | 
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I have got collapsible Summicron 5cm, 1:2. A strange thing on this lens is that the view through the lens is yellowish. Of course, there is no filter is placed on the lens. Intensity of the yellowness is almost darker tinted UV filter but it is yellow. I don’t think this is normal, am I right? Dose anybody know why the lens is yellow? Is there any way to restore the yellow lens? Other than this problem, the lens is in reasonably good shape. Please give me your help. Thank you in advance. |
Sean OKeefe
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 25, 2004 - 06:15 pm: |
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You havce a yellow glass summicron.
http://mejac.palo-alto.ca.us/leica-users/v02/msg11729.html |
Jan Dvorak
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 25, 2004 - 06:26 pm: |
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Iwasakisan,
These early 'yellow glass' Summicron lenses used a slightly radioactive glass. You should wear lead lined gloves when using it...
....Just joking.
Actually, even early Asahi Pentax Takumars exhibit the same yellowing phenomenon and apparently used slightly radioactive glass as well. Of course there is no danger in using these lenses, contrary to my statement above. The only problem is that the yellow cast will show on slides, if that is what you use. For B/W use you will see no difference.
All the best,
Jan |
Taka Iwasaki
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 25, 2004 - 06:55 pm: |
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Thank you very much Sean and Jan!!!
I knew radioactive materials were used to old lenses, but didn't know it turned to yellowish.
I'm fairly new to collecting vintage cameras.
It is like quicksand, I'm stucking in deeper and deeper. Thanks again! |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 26, 2004 - 08:09 am: |
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I know the yellow can be removed from Pentax 50mm f/1.4's by sunbathing them. The yellow was not there when the lens was new but rather a product of time and radioactivity. The sunbathing routine goes like this:
First turn the aperture to full open and set focus to closest position. Next wrap the entire lens in aluminum foil leaving only the front element open. Basically the sun goes in and turns around and exits through the front element. Sitting on the window sill for three or four days should do it. Check its temperature. Don't let it get too hot or the grease will start to flow. Normally the temperature doesn't rise much.
I don't know if this will help your Summicron. It did wonders to my Takumar.
Henry |
