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Thread: Replace old Cold Light head with LED light source?

  1. #1

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    Replace old Cold Light head with LED light source?

    Am using an older 5x7 Beseler enlarger that came from the factory with a cold light head. It is old and the light is feeble.

    Anyone with knowledge or experience in what kind of LED lighting might work to put in its place?

    Doesn't have to specifically fit in the old head as can modify to make it a bit larger if needed. Quick on and off is more important - as if I were using the condenser head with light bulb.

    Am asking so I don't make the normal mistakes and end up doing it three or four times before I get it to work.
    I tend to procrastinate on stuff. One of these days I'll do something about it.

  2. #2

    Join Date
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    Re: Replace old Cold Light head with LED light source?

    Not knowing the cold light head details this may be easy or not. My first LED head was build on an old Omega E3 by pulling the internals from the cold light head and replacing them with a constant current driver and 12 high power (3W) Cree XPG LEDs on a star. These were screwed to a sheet of 1/4" aluminum for support and a heat sink. A piece of opaque plexiglass provides diffusion. The hardest part was getting the LEDs arranged to provide even light. A 3x4 grid evenly spaced resulted in a bit of a hot spot and I ended up making a pencil mask to dim the center. Live and learn.

    I used a Meanwell LPC-60 driver. Turns on very quickly - seems much faster than an incandescent bulb takes to heat to full brightness - but I haven't tried to time the two. The spec sheet indicates a 500ms setup and 120ms rise time but the light seems to come on simultaneously to the relay in my timer closing.

  3. #3
    Photographer
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    Re: Replace old Cold Light head with LED light source?

    Keith Pitman

  4. #4

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    Re: Replace old Cold Light head with LED light source?

    Keith, thank you for the link. Missed it when I initially did a search. Probably didn't put in the right terms.

    Appears as if it may be something I can do or get done.
    I tend to procrastinate on stuff. One of these days I'll do something about it.

  5. #5
    Tin Can's Avatar
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    Dec 2011
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    Re: Replace old Cold Light head with LED light source?


  6. #6

    Re: Replace old Cold Light head with LED light source?

    LED Lighthead v1 BottomAssembly by Nokton48, on Flickr

    LED Lighthead Strips TopAssembly by Nokton48, on Flickr

    Looks doable to me. Total cost around 300 Bucks?
    “The secret of getting ahead is getting started.”
    ― Mark Twain

  7. #7

    Join Date
    May 1999
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    512

    Re: Replace old Cold Light head with LED light source?

    I would advice to made something like Daniel`s setup. Easy and effective. I would also place the LED lamps alternatively, instead of making a square grill.
    You should check the diffuser to LED stage distance, for full power and to avoid hot spots, so design it thinking on a possible height positions.
    My only issue with this design is the lack of power, you must find a really powerful LED strip. Cheap supermarket ones may not work. So make the LED chassis or plate designed to be easily upgraded or replaceable, or maybe, ready to be used with differently powered LED plates (instead of a more complex dimmable system).
    My problem with much stronger LED units is the hot spot, as Larry experienced. Strong LED units work better on condenser head types.
    BTW, the filter drawer is nice, but not a must IMHO. I have it but rarely use it on larger formats. I prefer a good under-the-lens system, faster and way more practical (e.g., for split printing).

  8. #8
    Greg Davis's Avatar
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    Nov 2009
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    Kentucky
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    Re: Replace old Cold Light head with LED light source?

    Neewer makes led panels that can range from 3200K to 5500K white light. They are meant for lighting photos and videos, but they are lightweight and inexpensive ($80). You would have to filter your contrast separately, but they are readymade if you do t want to build something.

  9. #9

    Re: Replace old Cold Light head with LED light source?

    Sheets of Rosco Gel apparently work well for split-filtering VC paper. Not expensive at all at B&H
    “The secret of getting ahead is getting started.”
    ― Mark Twain

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