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Thread: LED lighting for wet plate collodion

  1. #21

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    Re: LED lighting for wet plate collodion

    It’s been a few years since I shot wet plate (I miss it) however when I first set up to do portraits in wet plate I bought two large LED lights and it was a pretty miserable experience. They simply don’t put out enough UV light for wet plate. I returned the lights and bought two large flurencent lights and it worked much better. I got my exposures below 20 seconds but it was a lot of light on my models. It was difficult for them to look natural and not squint.

    Unfortunately the company that made the ones I bought, Fotodiox, stopped making the ones I bought. But you can see them on this link to Amazon. Maybe that will give you an idea for one to build.

    -Joshua

  2. #22

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    Re: LED lighting for wet plate collodion

    So this thread recapitulates the myth that collodion is primarily UV-sensitive. I think the myth probably is so tenacious because printing processes of the same time period, being mostly iron based, *are* nearly exclusively UV sensitive. I have only seen two rigorous investigations of the spectral sensitivity of collodion, both performed by Mr. Lund. The results varied slightly, most likely because collodion salted with different compounds was used in each test. In one, no meaningful UV sensitivity was observed. The collodion was primarily violet sensitive with some blue sensitivity extending into the low cyan. It was basically "blind" to UV. In the other test, the collodion was most sensitive to deep violet with a small amount of deep blue sensitivity and a meaningful amount of very, VERY near-UV sensitivity.

    Taking that small amount of actual objective evidence, choosing a light source for UV is primarily about finding a source with immense output in the violet and very deep blue range. Something with an emission centered on 450nm would be the best compromise between the two different collodions Mr. Lund measured. Thankfully, 450nm extreme deep blue LEDs are easily available. Simply build a light panel, light strip, whatever, out of these specific LEDs and you'll get the shortest exposure times with the least discomfort to your subject of any continuous light source. Because you're only putting electricity towards making exactly the photons the collodion can see, you'll end up using tremendously less power than you would for a wide-spectrum lightsource like a fluorescent or HMI as well as having a lower perceived brightness even though your exposures are much shorter.

  3. #23
    Tin Can's Avatar
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    Re: LED lighting for wet plate collodion

    Won’t cost much to find out.

    I wonder if anybody will try this.

    https://www.amazon.com/Led-World-Roy.../dp/B01CJM4K4I

  4. #24

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    Re: LED lighting for wet plate collodion

    Quote Originally Posted by Randy Moe View Post
    Won’t cost much to find out.

    I wonder if anybody will try this.

    https://www.amazon.com/Led-World-Roy.../dp/B01CJM4K4I
    On top of the cost of that, you need a hell of a heat sink, a fan to push air through the heat sink, and a power supply/driver. The amazon listing is just for the COB, not a workable system. I did find an eBay auction last night for someone selling all the bits to make a 100W light source at 450nm for around $50, but it's bare bones mad scientist looking stuff. I'd love for someone to spend the money to see if 50W of 450nm is enough to make a plate in a short amount of time.

  5. #25
    Tin Can's Avatar
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    Re: LED lighting for wet plate collodion

    Quote Originally Posted by williaty View Post
    On top of the cost of that, you need a hell of a heat sink, a fan to push air through the heat sink, and a power supply/driver. The amazon listing is just for the COB, not a workable system. I did find an eBay auction last night for someone selling all the bits to make a 100W light source at 450nm for around $50, but it's bare bones mad scientist looking stuff. I'd love for someone to spend the money to see if 50W of 450nm is enough to make a plate in a short amount of time.
    Most likely also need a white light to focus. 500 Watts of LED is overkill. 100 Watts might work.


    Everybody here is a Mad Scientist.

  6. #26

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    Re: LED lighting for wet plate collodion

    Simple wetplate lighting solution: walk outside, set up tripod. (Worked in 1860, works today)

  7. #27

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    Re: LED lighting for wet plate collodion

    Heheh. True. But not if I want to shoot a still life after work when the sun has gone down.

  8. #28

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    Re: LED lighting for wet plate collodion

    Quote Originally Posted by goamules View Post
    Simple wetplate lighting solution: walk outside, set up tripod. (Worked in 1860, works today)
    Unless it's cloudy

    or the model can't show up when the sun is in the right place

    or the client asked for a clothing level that might result in a call to the police by the neighbors

    or it's cold

    or the client wants a background that you can't pull off outdoors


    Be serious, there's a reason photo studios exist and why artificial lights exist.

  9. #29
    Tin Can's Avatar
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    Re: LED lighting for wet plate collodion

    I’m glad you can walk. I like studio work and I can do it even though my body is failing.
    I was walking recently, now barely. I’m not overweight, eat right but this last year has been one medical thing after another.

    I hope to regain my walk.

    Maybe I need a mule!

    I’ll check code here. 😜

    Quote Originally Posted by goamules View Post
    Simple wetplate lighting solution: walk outside, set up tripod. (Worked in 1860, works today)

  10. #30

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    Re: LED lighting for wet plate collodion

    Quote Originally Posted by Punker View Post
    Heheh. True. But not if I want to shoot a still life after work when the sun has gone down.
    For still life you can just pop a strobe a few times to get exposure. No need for anything fancy.

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