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  1. #11
    titrisol's Avatar
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    I'll take your word and expertise for it. My point is that the radiation levels are very samll and are not dangerous for humans or film.

    I have at least one of the "radiactive" lenses and I'm very happy with its performance, given it ii a 40 year old lens

    One of the things I have noticed is the use of the "Radioactive" term, whether it is true or not to raise the price at the auctions, given the "legendary status" you mentioned.


    Quote Originally Posted by Ole
    Newer lenses with similar but "cleaner" glass are better. QV the Cosina-Voigtländer APO-Lanthar 90mm - blows the competition right away, including the 1970's APO-Lanthar.
    Mama took my APX away.....

  2. #12
    Ole
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    Quote Originally Posted by titrisol
    I have at least one of the "radiactive" lenses and I'm very happy with its performance, given it ii a 40 year old lens
    So have I, and I'm not selling it!!!

    The radiation levels are low, but I wouldn't put it under my pillow. The chance of getting unhealty doses by normal use are practically zero, but if you were to eat it (or sleep with it under your pillow) it's a different matter.

    I have also noticed that use of "radioactive", and sometimes worry if we're heading back towards the "Radium Health Spa" craze...
    -- Ole Tjugen, Luddite Elitist
    Norway

  3. #13

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    JJS Thank you for the information. My posting was meant as a tongue in cheek comment regarding a radioactive lens.

  4. #14

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    Quote Originally Posted by jjstafford
    Supposedly Zeiss changed the compound formula for the 38mm Biogon in order to comply with new strident pollution control regulations. Do you know if that has anything to do with Lanthanum-glass?
    They got the lead out.

  5. #15

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    [COLOR=Red]Certainly not - unless your watch was made no later than 1930.[/COLOR]

    Not so. I've got a watch made in the 70's, it’s one of those self-winders with a luminous dial. It's the luminous dial that gives off radiation.
    Many if not most of the workers in the UK who assembled instrumentation on ww2 fighters and bombers (a luminous paint was used on the dials) got throat cancer. They used to find it helpful to lick the brush now and again I believe. I'd imagine the pilots got a fair old dose considering the number of dials and how crude the luminous paint was, but that was the least of their worries!

    A few years ago one of the mechanics at work (I work in a nuclear power station) set of the personnel monitor on leaving the nuclear island. It turned out he had his good watch on that day by mistake, it was an Adidas model (I think)with a luminous dial. It was a modern watch anyway. Strictly speaking it should have been declared a source and not allowed off site. As the contamination was 'fixed' he was allowed to take it home. He was also advised to contact the manufacturer for a replacement or refund, as while it was a weak source it was clearly not a good idea to strap it to one's wrist for days on end.

    Like wise that smoke alarm. Stick it in your pocket and given some time it will have a detrimental effect on your health. However screw it to the ceiling and it's perfectly safe. As we say at work, double your distance, quarter the dose.

    Oh I still have my old watch, but I certainly don't wear it anymore.
    As for radioactive lenses. I'd expect the radiation to be much lower than that of luminous watches and fire alarms etc, but I'm only taking a guess.

    Your local school, college, university, hospital or nuclear power staion should be able to check and advise.

  6. #16
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    OT - Radioactive marbles

    I've got a couple of marbles made from this type of glass. They actually glow in the dark, albeit weakly.

  7. #17
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    Wow, fascinating stuff - the lens looks pretty modern... being an FD mount Canon, it can't date back morethan what - early-mid 70's?
    The convex element is also something I have not seen before, but seems to make logical sense when you think about it...
    Again, fascinating!

    Now, I don't know if this is an urban legend or not, but there is a story in my family about a family member who worked as forced labour in a German instrument factory. She took ill and died, eventually, and the family was allowed to claim the body. In those days, the visitation was usually held in the persons home, the body lying "in state" usually in the biggest room of the house... All was well until during the night, the wind blew out the candles... The mourners were all of a sudden faced with a very..."luminescent" relative...

    I have no idea how true that story is, but its a part of the family "folklore" if you will - I know the person was real, and that she died during the war, and was in fact taken to Germany as a forced albourer. That much is documented...the rest is very much word of mouth. The story goes on to include a lead coffin...and I guess it could be easily verified, but no one saw it as important enough to disturb the rest of the deceased (and most likely, rightfully so).

  8. #18

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    FWIW, I once ran across a page about radioactive FEDs. (The FED was a brand of Soviet, and post-Soviet Ukrainian, rangefinder camera. It was originally a Leica clone, but evolved independently over the years.) It's basically the same story described in this thread, but the page has some quantitative measurements of the radioactivity of the FED's lens, measured in a high school science lab. The level was about 40% of background radiation (so total dose was 140% of background). This was measured, if I read correctly, in direct contact with the lens's front element.

    I don't know if the numbers would be similar for the Canon lens in the referenced eBay auction, of course.

  9. #19
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    Well, here's the thing to remember: "background" varies from place to place. I used to live in Seattle, where the background was very low -- most of the local ground was glacially deposited mud and gravel, which itself was originally sedimentary in origin; the ground there is just less "hot" than some places. Now, I live in North Carolina, where I understand one of the reasons most houses don't have basements is that radon buildup is a real problem -- there's enough thorium in the bedrock and overlying clay to significantly raise the background here.

    I'd bet I'm getting more "extra" radiation above the low background I've lived in for the past 20+ years from the soil than from the radioactive element in Super Takumar 1.4/50 -- and I can't put the ground in another room or get further away from it to attenuate the radiation.

    In any case, 40% above average background is really, *really* not a big deal. You don't see a huge increase in cancers in the thorium belt on the eastern slopes of the Appalachians, where the background itself is 2-3 times what it is in Seattle (except where basements concentrate the radon exuded from the ground), after norming out lifestyle differences. Smoking is MUCH more dangerous, even than basements full of radon...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

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