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Thread: Color modulation question

  1. #21
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    Quote Originally Posted by Vectorfire View Post
    That makes sense. The ILDA website is trying to ensure that promoters don't sign off on an under-powered show that will look lame. In the other thread you started, I also assumed you were thinking about a commercial show, which is why I initially recommended higher powered lasers. But for home use, it's just not an issue because you can always control both the light level and the fog with great precision.

    How does one quantify beam quality?
    As a general rule, you look at beam diameter and divergence. Lower is better in both cases.

    A typical 2 watt projector will have a 3 to 4 mm beam at the aperture and roughly 1 mrad divergence. Anything over 1.4 mrad is a sign of poor quality, as would a beam diameter larger than 4.5 mm (at least for this power level). Some higher-quality units might have tighter beams.

    Adam

  2. #22
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    Quote Originally Posted by buffo View Post
    A typical 2 watt projector will have a 3 to 4 mm beam at the aperture and roughly 1 mrad divergence. Anything over 1.4 mrad is a sign of poor quality, as would a beam diameter larger than 4.5 mm (at least for this power level).
    Not necessarily I don't think. It's not uncommon for lower powered aerial projectors to intentionally have higher divergence. 1.5-2mrad would not be ideal 500 feet out, but if your maximum throw in a club is 200 feet the thicker, higher divergence beam catches more haze.

    Also it's common practice now with higher powered gear to go for larger beam diameter, lower divergence for a longer throw, so you may see something like 1mrad on a 40 watt projector, but with an 8-10mm beam

  3. #23
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    I agree that with high power projectors you often will see larger beams at the aperture, and I also agree that for outdoor, long-throw use the trade-off for lower divergence makes sense in that case.

    But in the 2 to 3 watt range, most of the projectors I've used have roughly a 4 mm beam at the aperture. At this power level it's quite possible to have a 4 mm beam with ~ 1 mrad divergence without spending a fortune on optics. Blowing the beam up to a larger diameter at the aperture might make the beams more visible, but it also cheapens the effect in my opinion. (I prefer narrow beams.)

    Furthermore, trading beam diameter for divergence in a low power projector doesn't really make much sense, especially for indoor use. If you have a long enough throw in an indoor show where you are concerned about having the lowest divergence, then you're going to want more than 2 watts of power anyway because it means you're in a large arena and will need that power to fill that large volume - fat beams or no.

    I'll grant you that style does come into play though. Some people do like "fat beams", and I get that. As for me, I prefer narrow beams. And if a 2 watt projector has 2 mrad divergence, I feel cheated.

    Adam

  4. #24
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    I agree completely that in a 2W 4mm at 1mrad is not difficult, I don't know of any projectors on the market outside of the chauvet scorpion that are 2mrad at below 10 watts as standard, but don't underestimate the power of high divergence and diameter in short spaces. Check out Brad's X-Pods at some point, the greens are only 50mW but because they're a huge beam with high divergence and aren't moving, they look way brighter

  5. #25
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    They absolutely do. I've seen a few things the LD for Echoes (the tribute band I do lasers for) has done with the X-Pods, when I haven't been available with projectors and it's crazy how bright they look.

    https://www.facebook.com/bethany.rat...6454506656970/
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  6. #26
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    From my perspective as a manufacturer, it sucks. Like, it'd be very easy to say tighter beams and lower divergence are always better, also this wavelength is better than that wavelength and this control system is better than that one, but the reality is there's a shitload of nuance in this and getting deep into that nuance is one of the things that separates those who do great shows (rick) from those who spew flash and trash (me).

  7. #27
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    1W in the SELEM space which was not small was actually very bright. I was shocked how bright in fact.
    24W in the disco was insane and so bright it hurt. Therefore the proper power must be 12W.

    12W 0.5mRad 1mm beam

    Seriously though I think we sometimes get power fever. The amount of haze or fog makes a much bigger difference. IF you had just normal dust and 24w or a hazer and 1W they might be similar.
    For safety I'd go less power and wider beam with more smoke or haze. In this case though I'd use a telescope to decrease divergence but increase beam size. What I don't like is the flashlight like beams. IF you telescope up the beam looks more like a beam for a longer distance, is safer and more appealing.

  8. #28
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    Quote Originally Posted by buffo View Post
    Some people do like "fat beams", and I get that.
    "Let them eat" . . sharpies?? You can't hurt anyone under any conditions with non-coherent light.

    Sorry for the distraction.

    -David
    "Help, help, I'm being repressed!"

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    Don't be so certain... my American DJ Vizi Beam 5R's have a Risk of Fire warning sticker if aimed at anything closer than 15 meters! Suckers are bright!
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  10. #30
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    Ive seen videos of those babies cooking bacon! Id suggest that we do the same with a 25W laser, but we have enough bad press as it is! 😅
    "Help, help, I'm being repressed!"

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