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  1. #11

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    Dec 2002
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    Quote Originally Posted by MurrayMinchin
    It seems Calumet has finally figured it out, and it's now available;

    http://www.calumetphoto.com/item/EN6400.html

    They used 24 1 watt emitters for a 4x5 light source.

    Murray
    At that price, I think I will pass.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

    Visit my website at http://www.donaldmillerphotography.com

  2. #12

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    If any of you are considering doing this, Ebay has 1 watt and 3 watt blue and green Lumileds for sale. $3.99 each for the 3 watt units and 9.99 for five of the 1 watt units.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

    Visit my website at http://www.donaldmillerphotography.com

  3. #13
    Sparky's Avatar
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    Jun 2005
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    There's a much newer breed of high-output LEDs out now - I remember reading about it a few months ago - I can't recall any specifics - but it might be worth doing the legwork on google.

  4. #14
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    This might be it. Though this is a fixture.

    http://www.mew.co.jp/e/corp/news/2006/0603-01.htm

  5. #15

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    Mar 2004
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    I have built a 4x5 LED head using 3 watt Lumileds and a buckpuck driver. There was a thread earlier this spring on it. It took a little longer to finish that I expected. Two problems I had to solve were light fall off in the corners with blue and heat. To even the blue light I ended up using the same number of green and blue LEDs. To solve the heat problem I added a fan to the head enclosure. It is working fine with very consistent exposures - it is at least two stops brighter than the Zone VI head I was using before. I have added a dimming function so that I can use longer times if needed. I would estimate that it cost about $400 for the LEDs, drivers, power supply, and assorted switches and components. If you like working on a project and have the time I would encourage you to go ahead.

  6. #16

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    Jun 2006
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    Earlier this year I built a 4x5 enlarger head using 8 royal blue and 12 green 1 watt batwing luxeon leds. You need more green than blue leds to get a consistent printing speed, although you will still have to slightly adjust the current thru each bank of leds. Also the royal blue will provide a slightly higher contrast range than the blue. Most people seem to be using the lambertian leds instead of the batwing. I used the batwings primarily because the luxeon web site stated that the batwing leds would provide more even illumination of a optical surface. My calculations verified what they stated but I haven't tested the lambertians. I mounted 16 of the leds in a 2.5 inch diameter circle, then added the additional 4 green leds right inside the circle. The leds I used were the bare emitters not the stars. They were attached directly to a heavy aluminum heat sink with thermal epoxy. The leds are about 5.5 inches from the diffuser. Hope this is helpful.
    Richard

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