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Thread: Flash powder

  1. #21

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    Quote Originally Posted by ralnphot View Post
    And your point?
    Maniacs usually need treatment.
    But they need to see what they are, and that they do, first.

    Perhaps you could see that post in that light, and understand its point then?

  2. #22

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    Quote Originally Posted by ralnphot View Post
    And your point?
    Don't get me wrong, I like a good flash as well as the next man. There's no law against setting off a flammable substance and singeing your photographic subject.

    You may want to have a fire extinguisher handy!:rolleyes:

  3. #23
    Denis R's Avatar
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    thanks to NPR

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  4. #24
    df cardwell's Avatar
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    Denis,

    Yep, that's about the size of it. A few decades ago,
    flash powder was fairly easy to get, and we used it in the theatre for .... well, flashes.

    Take a normal plug fuse, remove the window, and apply the flash powder.

    It was, if I recall, desirable to be sure the circuit was broken before you added the flash powder,
    and the deluxe version of the gadget had 2 plugs, one with a neat little red light bulb to show whether you were hot.
    You tended to use these on a larger stage, rather than in a small studio space.
    Don't ask where that morsel of information came from. :o

    I suppose in today's refined times, this would be considered a bomb,
    and that is probably right. Use a number 2 flash bulb instead.

  5. #25
    Aurum's Avatar
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    Quote Originally Posted by ralnphot View Post
    And your point?
    Disappeared over the horizon, on fire, and accompanied by large quantities of smoke several posts ago!

    I'm also not sure where my eyebrows landed
    "Flatter Me, and I May Not Believe You. Criticize Me, and I May Not like You. Ignore Me, and I May Not Forgive You. Encourage Me, and I Will Not Forget You."

  6. #26
    Michel Hardy-Vallée's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    The carbon arc lamp was popular for many years as they could remain lit for hours. In fact, they are still used in some places for lighting large areas for photography.

    PE
    I heard they had the interesting side-effect of generating a ton of UV light, thereby slowly disintegrating the retinas of the talent lit with it.

    Also of interest to the discussion are flash sheets. They were sheets of quickly flamable substances that were lit in a special holder.

    The sheets:
    http://www.nwmangum.com/Kodak/FSheets-1.html

    The holder:
    http://www.nwmangum.com/Kodak/FSH-1.html
    Using film since before it was hip.


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  7. #27

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    Carbon arc lamps: beware, there's a lot of UV emitted, and your eyes won't feel any pain, but can become badly burned.

    As I understand, flash powder was composed partially of calcium oxide. Some reaction heated it to incandescence. Hence the word limelights for theatre footlights, which, I assume, had some system of injecting a steady flow of calcium oxide into or near a gas flame.

  8. #28

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    Quote Originally Posted by Larry.Manuel View Post
    Hence the word limelights for theatre footlights, which, I assume, had some system of injecting a steady flow of calcium oxide into or near a gas flame.
    Limelight was generated by heating a block of calcium oxide (Lime) using a hydrogen/oxygen flame. The light generated was a mixture of simple incandescence, and candoluminescence. That is the emission of light from the lime due to electrons that have been promoted to higher energy levels within the atomic structure, falling back to their base energy level, the energy being released in the visible spectrum. Thus the light is much brighter than would be expected simply from heating the lime to white heat.
    Steve

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  9. #29
    bsdunek's Avatar
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    Quote Originally Posted by Larry.Manuel View Post
    Carbon arc lamps: beware, there's a lot of UV emitted, and your eyes won't feel any pain, but can become badly burned.
    Yes! It's the same as watching an arc welder without protection. You can 'sunburn' your eyes, and that is very painful. There will be permenent damage to the retina too.
    Bruce

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  10. #30
    Aurum's Avatar
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    Good old arc-eye. Not a character from MASH, but bloody uncomfortable, like having a lump of grit in your eye. Got mine by being slack with the welding mask when MIG Welding the Landrover.
    As an aside electric arcs do generate enough UV when using them close up to give you a dose of sunburn. I'd reckon 20-30 minutes continuous in front of the torch=couple of hours on the beach without sunblock.

    Toasteeeeee!
    "Flatter Me, and I May Not Believe You. Criticize Me, and I May Not like You. Ignore Me, and I May Not Forgive You. Encourage Me, and I Will Not Forget You."

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