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  1. #1
    thefizz's Avatar
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    Special glass for passing more UV light

    I understand normal glass blocks most UVB light and that special glass can be got which allows more to pass. As a lot of alternative processes are sensitive to UVB light, I would like to get the best glass suited. Can anyone tell me what type to look for?

    Peter
    www.thephotoshop.ie
    www.monochromemeath.com

    "you get your mouth off of my finger" Les McLean

  2. #2
    Photo Engineer's Avatar
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    I believe it is quartz glass, but then some old uncoated lenses also pass a lot of UV.

    Quartz lenses cost an arm and a leg. Have your wallet ready.

  3. #3
    thefizz's Avatar
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    Sorry PE its glass for contact printing which I need rather than lenses.
    www.thephotoshop.ie
    www.monochromemeath.com

    "you get your mouth off of my finger" Les McLean

  4. #4
    David A. Goldfarb's Avatar
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    I haven't seen any print frames with quartz glass, so I suspect it's not a realistic option.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  5. #5
    Photo Engineer's Avatar
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    Quote Originally Posted by thefizz View Post
    Sorry PE its glass for contact printing which I need rather than lenses.
    It would still be quartz glass. Regular glass blocks some UV. But then, the big UV contact printers that I have seen use regular glass and just blast away!

  6. #6
    David A. Goldfarb's Avatar
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    Here's a price list:

    http://www.escooptics.com/windows/co...ed-silica.html

    So 3/16" is $20/sq. in., which if I've had enough coffee amounts to $1600 for an 8x10" sheet, presuming they make it that large. Don't drop it! Maybe better get 1/4" to be sure it can take the pressure of the springs.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  7. #7
    Ian Leake's Avatar
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    I suspect that you're over-engineering a solution to a problem that is purely theoretical. Ordinary glass is fine, and the simplest way to decrease your exposure time is to add more lights.

  8. #8
    AgX
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    Quote Originally Posted by Photo Engineer View Post
    It would still be quartz glass.

    Not necessarily Quartz. CalciumFluoride has high UV-transmission too and is thus used for UV-lenses.

  9. #9
    Bill Burk's Avatar
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    Here's where you can really do a reality check...

    For the process you are about to test...

    Put one sheet on top of "any" glass you want to test...

    And one sheet underneath

    Expose a step-by-step exposure series in f/stop series.

    Develop them up and find the "effective" density added by the glass.

    If it is negligible (or if the effective density is something you can work with), then you don't need anything better than the glass you just tested.

  10. #10
    Mustafa Umut Sarac's Avatar
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    Use ultra thin glass ! There are even paper thin flexible glasses available , good optical flat plastic would be answer also , fluro plates are better than cheap glass when it comes to index. I dont know they transmit uv or not but if they do , they are optically excellent.
    Can you please ask easier questions ? One Apug members request .

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