I think I have a radioactive lens!

Joined
Feb 2, 2005
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After reading a list of radioactive lenses, I tested the 44mm f/3.5 lens on my (inoperative) Signet 35 camera with my Pocket Geiger radiation counter. The background radiation level on my desk tested at 2 counts per minute twice and 3 cpm once. So I sat the lens directly atop the radiation sensor. This resulted in 6 cpm twice, and 5 cpm once for three separate measurements. This suggests a radiation level from the lens of 4 or 5 counts per minute. Now this is extremely low, which is consistant with everything I've read about thoriated lenses. I'm not surprised, the lens has a slight yellow tinge, indicative of aged thorium oxide. (It's like having an in-built yellow filter!)

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Joined
Sep 20, 2009
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16,275
I still have my radioactive super-takumar 50mm 1.4. I used it since I was 15 and occasionally still do on a sony a7ii.
The yellow tint can be removed by exposing the lens to uv light.
I don't mind the tint. Like you said, it's like having a light yellow filter permanently fixed.
 
Joined
Feb 2, 2005
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Due to the quantum effect, both are possible at the same time! Unless you look for the fungus that is, in which case it's either there or not there.

Seriously though, I don't believe that fungus would be affected by low level radiation. In the 60s, Brookhaven National Labs did an experiment on the effect of radiation on all kinds of flora. Fungus and bacteria were the last to succumb, but eventually everything in the forest they irradiated died. Where the bacteria and fungus were dead, there was no decay. Very eerie!
 
Joined
Mar 25, 2011
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London
Can I get enhanced vision if I use my Kodak camera everyday?
That would be a lot less than the Six Millions a not so secret US agency spent in the ‘70s on one astronaut to rebuild him, make him faster and better.
 
Joined
Feb 2, 2005
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Arizona
Norm McDonald's bit on the Six Million Dollar Man - on YouTube
Could they even do a single eye for six million dollars today? Probably not. Good thing the show was made so long ago. The sixty five billion dollar man doesn't have the same ring to it.

ps, you'd get slightly dehanced vision, as I believe even a slight increase in background radiation will speed up the formation of age-related cataracts.
 
Joined
Jan 22, 2019
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598
Location
St. Charles, IL
Real Name
Andy
I still have my radioactive super-takumar 50mm 1.4. I used it since I was 15 and occasionally still do on a sony a7ii.
The yellow tint can be removed by exposing the lens to uv light.
I don't mind the tint. Like you said, it's like having a light yellow filter permanently fixed.
I recently dug my old Spotmatic out of storage and found a yellowing SMC Takumar on it. Now I leave it near the basket of apples to try to keep the fruit flies away. It doesn't do well in that respect, but I found it to be very sound optically:
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