Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,906   Posts: 1,555,859   Online: 876
      
Page 3 of 6 FirstFirst 123456 LastLast
Results 21 to 30 of 59
  1. #21
    benjiboy's Avatar
    Join Date
    Apr 2005
    Location
    U.K.
    Shooter
    Multi Format
    Posts
    6,908
    "I did find it fascinating how a discussion on radioactive lenses could quickly lead to over population. Ben must have a reputation ;-"

    That's right Dave the question was about Thorium in lenses, not lead in my pencil
    Ben

  2. #22

    Join Date
    Sep 2002
    Location
    Omaha, Nebraska
    Shooter
    Multi Format
    Posts
    2,512
    Images
    4
    I have read that Aero Ektar lenses produced by Kodak used glass with Thorium. These lenses are pretty fast (2.5) and I have thought about getting one for wet plate. The radioactivity gave me a little pause, but as others have pointed out the glass "browns" over time and I don't know how this would effect the speed of the lens or transmission of UV rays, both critical for wet plate.
    "Fundamentally I think we need to rediscover a non-ironic world"
    Robert Adams

  3. #23
    BetterSense's Avatar
    Join Date
    Aug 2008
    Location
    North Carolina
    Shooter
    35mm
    Posts
    2,876
    Coleman stove lantern mantles contain thorium, too. When the lamp is first lit, the silk burns off, and a thorium oxide skeleton remains, which becomes incandescent in the gas flame.
    They don't anymore, although I understand that you can still get cheap chinese mantles that incorporate the thorium. It seems like thorium lamp mantles belong to a growing group including things like incandescent lightbulbs, CRTs, pseudoephedrine, robutussin, and other things that work too well and must be villified or banned.
    f/22 and be there.

  4. #24
    Ralph Javins's Avatar
    Join Date
    Jul 2008
    Location
    Latte Land, Washington
    Shooter
    Multi Format
    Posts
    832
    Quote Originally Posted by FilmOnly View Post

    I would be interested to know how the 50/1.4 S tests on correctly functioning equipment. The brownish tint of the lens gives me pause.
    For the tint of your lens, others have noted this also. One of the recommended cures is to place the lens without caps on a window sill in a south facing window for a few days (a week?) where sunlight can shine through the lens, and the coloration seems to go away. This also aflicted a couple of my Minolta AUTO ROKKOR-PF 1:1.4 f=58mm lenses. Some Asahi-Pentax Takumar lenses also show this effect.
    Enjoy;

    Ralph Javins, Latte Land, Washington

    When they ask you; "How many Mega Pixels you got in your camera?"
    just tell them; "I use activated silver bromide crystals tor my image storage media."

  5. #25
    mhcfires's Avatar
    Join Date
    May 2008
    Location
    El Cajon, CA
    Shooter
    Multi Format
    Posts
    556
    Quote Originally Posted by benjiboy View Post
    Aren't we getting a little off the point ?, my remark about Lead lined boxer shorts was a Joke.
    Lead lined boxers would be a little heavy. My back hurts enuff already.
    Michael Cienfuegos


    If you don't want to stand behind our troops, please feel free to stand in front of them.

  6. #26

    Join Date
    Jul 2008
    Location
    Southeastern U.S.
    Shooter
    35mm
    Posts
    550
    Please let me clarify...I do not own a Nikkor 50 1.4 S lens. However, I would like to conclusively verify whether or not that lens is radioactive. The brownish tint I see in photos of it gives me pause.

    I have already owned Takumar lenses, and have tried the "window sill solution" suggested above. After doing this, I still did not feel comfortable in owning radioactive lenses, and thus I sold them. I have no interest in owning any other radioactive lenses, as, in testing them, some have found what would seem to be problematic levels of radiation...levels that would concern me. In another thread, I have provided a link for one such test. I do not claim to be a chemist or nuclear physicist. I am simply one who would rather be "on the safe side"--especially since there are many other fine lenses out there.

  7. #27
    Sirius Glass's Avatar
    Join Date
    Jan 2007
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    13,188
    The amount of radiation in a lens is probably so low, that the background radiation from the bricks in your house or the wood in the furniture are very probably higher. Keep the lens, there are much higher source of radiation where you live and where you work.

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  8. #28
    MikeSeb's Avatar
    Join Date
    Jun 2005
    Location
    Prospect (Louisville), KY, USA
    Shooter
    Medium Format
    Posts
    1,062
    Quote Originally Posted by FilmOnly View Post
    After doing this, I still did not feel comfortable in owning radioactive lenses, and thus I sold them. I have no interest in owning any other radioactive lenses....I do not claim to be a chemist or nuclear physicist. I am simply one who would rather be "on the safe side"....
    You obviously are free to do as you wish. But this is one of the more ludicrously irrational things I've ever read on APUG.

    I hope you don't smoke or drive a car, given the real risks those activities pose. Radon in your basement? Use sunscreen? Climb a ladder?

    Good lord.
    Michael Sebastian
    Website | Blog

  9. #29

    Join Date
    Jul 2008
    Location
    Southeastern U.S.
    Shooter
    35mm
    Posts
    550
    MikeSeb: Your comments are offensive. You could have stated your opinion in a more civil manner.

    Be advised that I have already cited a link for a test in regard to the relative harmfulness of the radiation in such lenses. The person who tested it found more radiation than what had been previously found (or assumed). After performing these tests, the person parted with his radioactive lenses. Once again, I choose to make no assumptions--especially since there are many fine lenses out there.

    My position is certainly not irrational. It is better described as cautious. Camera equipment is not a necessity in life, and thus I prefer to err on the side of caution.

    Your taking of the Lord's holy name in vain is also not appreciated.

  10. #30
    MikeSeb's Avatar
    Join Date
    Jun 2005
    Location
    Prospect (Louisville), KY, USA
    Shooter
    Medium Format
    Posts
    1,062
    Quote Originally Posted by FilmOnly View Post
    MikeSeb: Your comments are offensive. You could have stated your opinion in a more civil manner.

    Be advised that I have already cited a link for a test in regard to the relative harmfulness of the radiation in such lenses. The person who tested it found more radiation than what had been previously found (or assumed). After performing these tests, the person parted with his radioactive lenses. Once again, I choose to make no assumptions--especially since there are many fine lenses out there.

    My position is certainly not irrational. It is better described as cautious. Camera equipment is not a necessity in life, and thus I prefer to err on the side of caution.

    Your taking of the Lord's holy name in vain is also not appreciated.
    Wow. You read a lot into a short post. It's a rare day when I'm able to combine blasphemy AND incivility in one simple post.

    I guess without the context provided by face-to-face contact, one man's blasphemy is another's frustrated skyward plea for reason to prevail.

    Have a peaceful and radiation-free Thanksgiving.
    Last edited by MikeSeb; 11-25-2009 at 10:31 AM. Click to view previous post history.
    Michael Sebastian
    Website | Blog

Page 3 of 6 FirstFirst 123456 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin