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Thread: LED Lamp House for Omega D- Series Enlargers

  1. #1

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    LED Lamp House for Omega D- Series Enlargers

    Hi all. I just wanted to let everyone know that I am offering a new design LED lamp house for the Omega D-series variable contrast enlargers. This product came out of work I did for myself to make a replacement for the incandescent bulb of my Omega D2. It turned out pretty well so I thought I would offer a few to other enthusiasts. It is being offered through eBay or by contacting me directly. I don't know if there is a market for this sort of thing and any suggestions would be deeply appreciated. Thank you.
    Attached Thumbnails Attached Thumbnails IMG_1118.jpg   IMG_1123.jpg   IMG_1126.jpg   IMG_1168.jpg  
    Last edited by cardiomac; 9-Jan-2012 at 07:29. Reason: Grammer

  2. #2
    bob carnie's Avatar
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    Re: LED Lamp House for Omega D- Series Enlargers

    I use 250 w bulbs for mine, heads are rated for 150w, but I like the extra strength .
    How much power would your system pump out compared to a standard 150w.
    is it more or less??
    Looks pretty slick.

  3. #3
    bob carnie's Avatar
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    Re: LED Lamp House for Omega D- Series Enlargers

    Also do you use the filters and drawers exactly the same?
    What grade would you consider the LED light without filters on a normal VC paper?

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    Re: LED Lamp House for Omega D- Series Enlargers

    Thanks for the compliment. I was using a 150 watt bulb in my D2 which puts out about 2300 lumens. My LED head puts out only about 550 lumens but the exposure times are about the same. I think this is because the LED light is directional whereas the bulb is not, so much of the light output of a bulb never makes it to the film. Also, the LED's are brighter in the blue-green region of the spectrum where paper is sensitive. In practice, the LED's function much like a 150 watt incandescent bulb but without the drawbacks.

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    Re: LED Lamp House for Omega D- Series Enlargers

    The filter drawer works normally except you don't have to worry about the filters melting during prolonged exposures. On Ilford MGIV in Dektol with no filter, I get about 8 steps on a Stouffer 21 step wedge which is the same as with a No. 2 Ilford filter. That translates to an ISO range of about 110, or a soft Grade 2 contrast.

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    Steve Smith's Avatar
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    Re: LED Lamp House for Omega D- Series Enlargers

    Is this just white LEDs? I have made an LED source for my enlarger using red, green and blue LEDs but I was thinking about trying a white LED source.


    Steve.

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    Re: LED Lamp House for Omega D- Series Enlargers

    These Cree light engines combine red-poor "white" LED's with red LED's to balance the spectrum. In an enlarger, the red light doesn't contribute to the exposure but it does make the image easier to see with the eye. I tried years ago to make a variable contrast light source using individually controllable blue and green LED's. Unfortunately, the blue LED's were not blue enough to get hard contrast prints so I abandoned the project after many, many hours spent on it.
    Last edited by cardiomac; 9-Jan-2012 at 08:20. Reason: Grammer

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    Re: LED Lamp House for Omega D- Series Enlargers

    How even is illumination at the easel, i.e. difference in stops from center to corner?

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    Re: LED Lamp House for Omega D- Series Enlargers

    Zero to less than a quarter stop. This was the biggest challenge in designing the lamp. Many hours were spent testing various reflector/diffuser combinations until I got one that worked perfectly. One of the key discoveries was that the lens needs to be curved to work properly with the condenser lenses on the enlarger. Another technique I used is to combine diffusive and reflective surfaces within the lamp to create an even light field at the lens surface. The evenness of illumination at the easel is directly proportional to the evenness of illumination at the lens surface. Also, note that the active area of the lamp lens is only the center 3 inches, not the entire surface. This mimics the geometry of an incandescent lamp and helps reduce stray light which "softens" the print.
    Last edited by cardiomac; 9-Jan-2012 at 09:07. Reason: Grammar, again.

  10. #10
    bob carnie's Avatar
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    Re: LED Lamp House for Omega D- Series Enlargers

    Well I am really impressed and would like to know the price of one of these suckers.

    I imagine the light falling on the easel is a bit softer than the tungsten bulb Y/N?
    How long or how many exposures do you figure as compared to a 150w?
    Quote Originally Posted by cardiomac View Post
    Zero to less than a quarter stop. This was the biggest challenge in designing the lamp. Many hours were spent testing various reflector/diffuser combinations until I got one that worked perfectly. One of the key discoveries was that the lens needs to be curved to work properly with the condenser lenses on the enlarger. Another technique I used is to combine diffusive and reflective surfaces within the lamp to create an even light field at the lens surface. The evenness of illumination at the easel is directly proportional to the evenness of illumination at the lens surface. Also, note that the active area of the lamp lens is only the center 3 inches, not the entire surface. This mimics the geometry of an incandescent lamp and helps reduce stray light which "softens" the print.

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