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Thread: Why can't other light sources be used to get tight (laser like) beams?

  1. #31
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    ... or 'think big!' - look at the old German flak searchlights - an arclamp with a fine arc-zone, a big concave mirror and a circular blind -- the resulting beam can be of some ten km visible length with a 'nearly laserlike' divergence

    Viktor

  2. #32
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    does anyone have suggestions for using a non-laser light with a mirror/galvo system? i'm doing some galvo light shows indoors and thought it would be cool to use something that felt more natural instead of the artificial feeling of laser light. i've tried this before by aiming a Leko Source Four into the galvos, but it was tricky because the Leko is focusable, and it was difficult to get it focused just right. i'm wondering if theres a tighter light source i could use thats easier and faster to set up for something like this. any ideas? the leko gets hot, and its big and heavy.

  3. #33
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    wow, the Wavien RLT flashlights suggested earlier in this thread look like a cool thing to try for my galvo system instead of a laser. does anyone know of anything that could be better than that?

  4. #34
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    Ah, Laser Emulation...
    ~


    The traditional way to simulate a laser is to throw away huge amounts of light. You start with an arc or halogen source, with a tiny, bright arc or filament. You run that into a "Condenser" Lens to collect and focus the light to a point. Then you focus an F1 or F1.2 Lens on it for best collimation, and then slightly "back off" the focus for uniform Kohler illumination. Then a mask is inserted between the source and the lens with a tiny hole in it, allowing the most parallel light to pass, and blocking probably 70-90% of the rest of the light energy.
    ~
    On a sunny day with a south facing window, you can place a piece of cardboard in the window to block the sunlight. Then place a pinhole in the cardboard and darken the room. You'll get the idea that this produces a highly diverging beam, that looks laser-like near the source, but is a blob across the room.
    ~
    It gets a bit better if you use a two lens telescope, but then you risk not fitting the beam on the scan mirrors.
    ~
    High End Systems Emulator.. My favorite non laser, scanning source....

    https://www.youtube.com/watch?v=op1SfJGDSG4

    The downside:

    https://www.youtube.com/watch?v=5Qwq5OnVGeo

    The scanner mirrors are paddles the size of a matchbox or more, the laws of Thermodynamics and Optical Etendue prevent you from getting anywhere near the small beam of a laser.
    The emulator scanners are low speed "actuators" without feedback to lower the costs.. So you can just get simple shapes...
    ~
    ~
    https://www2.highend.com/pdfs/produc...ulator_led.pdf


    Steve
    Last edited by mixedgas; 02-12-2016 at 08:18.
    Qui habet Christos, habet Vitam!
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  5. #35
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    Quote Originally Posted by mixedgas View Post
    High End Systems Emulator.. My favorite non laser, scanning source....

    https://www.youtube.com/watch?v=op1SfJGDSG4

    The downside:

    https://www.youtube.com/watch?v=5Qwq5OnVGeo

    The scanner mirrors are paddles the size of a matchbox or more, the laws of Thermodynamics and Optical Etendue prevent you from getting anywhere near the small beam of a laser.
    The emulator scanners are low speed "actuators" without feedback to lower the costs.. So you can just get simple shapes...
    ~
    ~
    https://www2.highend.com/pdfs/produc...ulator_led.pdf


    Steve
    ...ahhh! Those were super cool!

    I've also seen a VERY old system (circa early-mid 1980's) from Precision Projection Systems (PPS) which used a hefty arc lamp unit which contained some dichros, a shutter, and a fiber launch to a remote scanner ( a fiber-fed predecessor to their RGS-2D http://ppsfx.com/html/lasers.html ) . The remote scanner had a pair of G120s with ~5mm mirrors and some collimating optics plus the scan amps & control board. The PPS boxes were nowhere near as bright as the HES Emulators, though.

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