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  1. #11
    Jim Fitzgerald's Avatar
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    Quote Originally Posted by konakoa View Post
    I've got something a bit different. I'm using multiple rows of UV LEDs in a 20"x15"x1.5" box I made. It runs on 12 volts DC via a wall adapter, so I didn't have to handle 120 volt AC household wiring. It's also lightweight--the side walls and back are white foam board lined with aluminum tape to (hopefully) reflect any stray light back to the print. The whole thing collapses down to fit in a drawer for storage when not in use. The nicest part is the LEDs don't get hot at all; after hours of use they're only warm to the touch.
    Nice looking unit. What process are you doing and what kind of exposure times?

    Thanks,

  2. #12
    pinhole_dreamer's Avatar
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    Ooooh....gotta have my husband or one of the boys help me with this project!

  3. #13
    Mainecoonmaniac's Avatar
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    I like yours the best

    Quote Originally Posted by Jim Fitzgerald View Post
    Nice looking unit. What process are you doing and what kind of exposure times?

    Thanks,
    It's energy efficient to boot.

  4. #14
    Vlad Soare's Avatar
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    I use one of these.
    With cyanotypes and vandyke prints, it gives me exposures of five to ten minutes with unstained negatives, and about twenty minutes with stained negatives.
    It covers 8x10" with some room to spare. The contact printing frame in the attached picture is 9.5x12" (24x30 cm).
    Attached Thumbnails Attached Thumbnails IMG_8922_mic.jpg  
    Last edited by Vlad Soare; 02-11-2011 at 02:50 AM. Click to view previous post history.

  5. #15
    holmburgers's Avatar
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    Quote Originally Posted by konakoa View Post
    I've got something a bit different. I'm using multiple rows of UV LEDs in a 20"x15"x1.5" box I made.
    Absolutely gorgeous.
    If you are the big tree, we are the small axe

  6. #16

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    Quote Originally Posted by Jim Fitzgerald View Post
    Nice looking unit. What process are you doing and what kind of exposure times?
    Jim, I use it for cyanotypes and van dyke brown. I keep meaning to try it with some gum bichromate but other projects keep seeming to conspire to keep me from doing so.

    Exposure times vary for me. Generally, for a good full range cyanotype or van dyke brown print it takes an hour or two with my UV box.

    My exposure times are based off a Stouffer 21-step wedge. I make enlarged negatives from my original films with Arista lith film and my darkroom enlarger. Densities wander a bit when I do this, so exposure times in the UV box also vary on both sides due to the inconsistencies of my enlarged negatives. For cyanotypes, I can print about a eight stop range with a two hour exposure. For comparison, I get the same contrast range outside in the winter sun with about thirty minutes of exposure to direct sunlight. Van dyke browns are complete (seven stop range) in about an hour under the UV LEDs.

    My exposure times compared to others posted here seem long; I don't know if it's my light, paper, sizing, the formulas I'm following or the densities I'm expecting to see.

    (Thanks for the compliments Mainecoonmaniac and holmburgers!)

  7. #17
    Lee L's Avatar
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    Quote Originally Posted by konakoa View Post
    I've got something a bit different. I'm using multiple rows of UV LEDs in a 20"x15"x1.5" box I made. It runs on 12 volts DC via a wall adapter, so I didn't have to handle 120 volt AC household wiring.
    Am I correct in thinking you used these:

    http://www.superbrightleds.com/cgi-b...specs/NFLS.htm

    Lee

  8. #18

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    Yep! Same ones as in my LED enlarger.

  9. #19
    Lee L's Avatar
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    Quote Originally Posted by konakoa View Post
    Yep! Same ones as in my LED enlarger.
    Very cool. Thanks.

    Lee

  10. #20
    daleeman's Avatar
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    Quote Originally Posted by Vlad Soare View Post
    I use one of these.
    With cyanotypes and vandyke prints, it gives me exposures of five to ten minutes with unstained negatives, and about twenty minutes with stained negatives.
    It covers 8x10" with some room to spare. The contact printing frame in the attached picture is 9.5x12" (24x30 cm).
    What kind of uv source are you using. This looks like you store bought this? where can we find out more?
    Lee

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