Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,708   Posts: 1,548,582   Online: 1145
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1
    Jeff Bannow's Avatar
    Join Date
    Mar 2007
    Location
    Royal Oak, MI
    Shooter
    Medium Format
    Posts
    1,755
    Images
    41

    Copy stand - polarizing the lights to remove glass reflections?

    I've heard talk of being able to do this, but am not sure the actual process.

    I have one of these -Kaiser Copy Stand. The lights are a little different, but close enough. I see a kit for $900 that will add polarization to the lights, but there is no way I'm spending anywhere near that much.

    Is it as simple as adding polarizing screens over the lights? I just want to remove reflections from shiny objects when shooting from the copy stand.
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  2. #2
    Mainecoonmaniac's Avatar
    Join Date
    Dec 2009
    Shooter
    Multi Format
    Posts
    3,013
    Images
    6
    Roscoe makes polarizing gels. You also have to polarize the lens. Once the set up is finished, you look through the camera lens and put a coin on the copy surface then turn the polarizing filter on your lens until the the coin has no reflections. When this happens, the coin will turn black. You probably get a polarizing copy stand on Ebay for cheap with the advent of the flat bed scanner.

    Here's a link to some polarizing gels for your lights.

    http://www.filmandvideolighting.com/pofish19x20i.html

    Good luck.

  3. #3
    DWThomas's Avatar
    Join Date
    Jun 2006
    Location
    SE Pennsylvania
    Shooter
    Multi Format
    Posts
    2,245
    Images
    65
    One word of warning (don't ask me how I know): if you're using hot lights of any power, the heat can damage the polarizing gels unless they are spaced a decent distance from the lens. Even with two inches or so of airspace in front of some 500 W halogen worklights with glass covers, the polarizing sheet was starting to buckle in a matter of a minute or two.

  4. #4
    Jeff Bannow's Avatar
    Join Date
    Mar 2007
    Location
    Royal Oak, MI
    Shooter
    Medium Format
    Posts
    1,755
    Images
    41
    Interesting - I guess the $900 polarizers are glass instead of gels then?
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  5. #5
    DWThomas's Avatar
    Join Date
    Jun 2006
    Location
    SE Pennsylvania
    Shooter
    Multi Format
    Posts
    2,245
    Images
    65
    Quote Originally Posted by Jeff Bannow View Post
    Interesting - I guess the $900 polarizers are glass instead of gels then?
    I honestly don't know; it could be they set the polarizers a long distance from the lights and then to filter the expanded beam width have to use large sheets of the material which fattens up that price. I was pretty amazed at what that stuff costs.

    I had the vague impression that even glass polarizers are actually a sandwich with a plastic layer that has the eye of newt and batwings for polarizing, but I'm a few kilometers out of my depth!

    I'm also assuming here that you are talking of photographing three-dimensional shiny objects, as opposed to paintings and flat artwork under glass which isn't really that bad to do without polarizers, until you get into oil paintings with lots of surface texture and shiny varnish or art with embedded glitter.

  6. #6

    Join Date
    Jul 2007
    Location
    Netherlands
    Shooter
    Medium Format
    Posts
    5,686
    All polarizers are indeed polyester or polyvinyl (i forget) sheets, even those glass ones: they are such sheets sandwiched between two glass blanks. The structure of the polyester/polyvinyl (whatever it is) is what does the business that makes them polarizers.
    Not having tried this myself (they cost too much) i don't know how they absorb heat, and what they then do.

  7. #7
    Steve Smith's Avatar
    Join Date
    May 2006
    Location
    Ryde, Isle of Wight
    Shooter
    Medium Format
    Posts
    8,609
    Images
    122
    Polyvinyl dipped in iodine and stretched (from what I can remember). I'm sure there are other methods but that was Edwin Land's method to make large and cheap polarisers.


    Steve
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  8. #8
    Mainecoonmaniac's Avatar
    Join Date
    Dec 2009
    Shooter
    Multi Format
    Posts
    3,013
    Images
    6

    Mount them at a distance and...

    Quote Originally Posted by Jeff Bannow View Post
    Interesting - I guess the $900 polarizers are glass instead of gels then?
    Mount them about a foot away and get a copy stand with a foot switch to turn on the lights when you need them. That way they don't have be on constantly. The bulbs won't last as long, but it will allow you to cool off also.

  9. #9
    Greg Davis's Avatar
    Join Date
    Feb 2004
    Location
    Crestview Hills, KY
    Shooter
    8x10 Format
    Posts
    1,934
    I do this when I do copy work for painters. I put the Roscoe polarizing gels over the lights and a polarizing filter over the lens and eliminate all the glare/reflections. It produces cleaner work.
    www.gregorytdavis.com

    Did millions of people suddenly disappear? This may have an answer.

    "No one knows that day or hour, not even the angels in heaven, nor the Son, but only the Father." -Matthew 24:36

  10. #10

    Join Date
    Feb 2003
    Location
    Floriduh
    Shooter
    35mm
    Posts
    2,272
    Images
    2
    It's possible to put a heat resistant diffuser over the lights which are at a 45 degree angle, and there might be a heat resistant PL but if not it's easy enough to improvise a mat gel holder. There is also the shooting tents for table top items that has a hole on top for the camera. You light thru the sides with a strobe. Any glare can be controlled at the lens.
    W.A. Crider

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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