8X ND filter: UV warning

Discussion in '35mm Cameras' started by Charlie Dilks, Dec 6, 2003.

  1. I just received a Hoya HMC 8X ND filter.
    In the box is a circular insert that says:
    UV Alert
    large !... UVA: 320nm - 380nm
    two large !!... UVB: 280nm - 320nm

    That's all it says. What's the alert?
    Does it =not= block those wavelengths? Does it block them more than
    usual?
    What is the significance?
    TIA
     
    Charlie Dilks, Dec 6, 2003
    #1
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  2. Yes, UV Light pass through the filter, you can see spectral transmission
    diagramms for many hoya ND filters at:
    http://www.hoyaoptics.com/color_filter/neutral_density.htm

    This means: Don`t use the filters with long lens an look through your
    camera to the sun, it may visual looks good, but cause the UV pass full
    through the filter your eys will hurt. Probably your camera get´s damaged
    too.

    Eventually your eys will even hurt, if you use it without lens to look at
    the sun: Your eys get less illumination --> get wide open. And the UV paas
    throuh an burn your retina.

    Markus
     
    Markus Keinath, Dec 6, 2003
    #2
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  3. Thanks a lot for the info Markus.
     
    Charlie Dilks, Dec 6, 2003
    #3
  4. Charlie Dilks

    Doug Payne Guest

    It's probably the standard not-very-well-worded warning for those who
    might use one of these to look at the sun, particularly during a solar
    eclipse.
     
    Doug Payne, Dec 6, 2003
    #4
  5. Charlie Dilks

    Alan Browne Guest

    I believe the lens of the eye is most affected by UV with cataracts
    resulting. There may be retinal damage too.
     
    Alan Browne, Dec 6, 2003
    #5
  6. Charlie Dilks

    Slingblade Guest

    I would imagine it means that if you plan to look at the sun with this
    filter attached that you should be warned against it, as it could
    cause eye damage.
     
    Slingblade, Dec 7, 2003
    #6
  7. Charlie Dilks

    raymondlo84

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    The little circle path is a light sensitive material. If you have that exposed to the sun it will turn blue.

    If you have a UV filter on top, it will remain the same color as long as the filter is effectively reducing the UV light. ;)

    IT IS NOT JUST A WARNING SIGN! :) It is a piece of special paper that let you test out the filters :)
     
    raymondlo84, Oct 4, 2012
    #7
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