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Thread: Power suggestions for outdoor shows

  1. #1
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    Default Power suggestions for outdoor shows

    Hi! First time poster.

    I've taken on lighting design & programming for a small group that throws parties a few times a year in various settings. I'd like to add a laser element to our production, after falling in love with some of the beam and liquid sky effects you can achieve with RGB projectors these days. I will likely start with QuickShow and some sort of cheap Chinese option. I'm stuck on figuring out what sort of power I need to make it all worthwhile.

    Our typical outdoor venue will be:


    • Pretty dark woodsy environment, with most of the immediate lighting under my control
    • 100 to 250 foot open space between projector and woods or whatever else the beam eventually hits
    • 50 to 300 in the audience
    • Sometimes we get lucky and have some fog, but generally no haze or fog machines available


    Other venues it would be used at, but less important than the above:


    • Small to medium warehouse spaces
    • Open desert spaces


    Given that, would a 3W or 5W RGB projector give me bright, visible beams and liquid sky effects? Projecting onto the trees will get a cool secondary effect, but I'm really looking to have visible beams over the dance floor itself. We also use a lot of deep purple/blue/aqua colors, which I know aren't the brightest for a laser to recreate.

    Second question, I've been combing through a lot of threads about cheap Chinese lasers vs. namebrand models. I understand the variance and image projection quality can be quite variable, but what about the power ratings? Is a 2w blue beam from China going to be equivalent to a name brand? Or are they pumping up ratings? Maybe other components matter more to perceived brightness? I went through these same issues buying cheap LED lighting, you just really don't know what you're going to get until it shows up.

    Thanks for any help! Really to avoid getting something "lukewarm" in power.

  2. #2
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    First, are you located in the USA? If so, you'll have to consider the regulatory side of things before you start.

    Assuming you are in the US, then you'll have to very narrowly define these "parties". Because 300 people sounds suspiciously like a concert or festival, and if it's open to the general public (and especially if there is any sort of commerce involved), then CDRH rules will apply and you'll need to use certified, legal projectors and obtain your own laser light show variance.

    That being said, if you can somehow claim that this is a private event and there is no commerce involved, then you may be able to sidestep the CDRH requirements. (Be mindful of state requirements though, especially in Florida, Arizona, or New York.)

    Regarding the question of how much power is enough: When it comes to outdoor shows, you always need more power. (Always) Outdoor shows are a pain in the ass because it's so difficult to control the environment. You never know how the show is going to look. And if you can't rely on having fog or haze present, you will need STUPID high power levels to pull off a convincing liquid sky.

    For 300 people in a space no larger than 200 ft on a side, you could get away with a few 5 watt projectors if you had control over the other lighting (so you could dim those lights while the lasers were on) and you could adequately control the fog/haze so you had more or less uniform coverage over the audience area. Typically this would be done with 3 or 4 fog/haze machines with fans placed adjacent to each unit. The idea would be to position the foggers/hazers up-wind so the medium will spread through the audience area as the wind blows. But the machines need to be attached with long extension cords so they can be re-positioned as the wind dictates.

    The problem, of course, is that the wind is unpredictable. A sudden wind shift can rob your entire projection area of fog in a matter of seconds, and without any fog in the air even a 5 watt laser projector will look lame as hell. (Seriously - without fog your liquid sky effects will be all but invisible, and beams viewed from the side will likewise be nearly impossible to see. Only beams viewed directly from the projection angle will be noticed, and even they will be quite dim.)

    Note also that even if you have a fogger/hazer positioned at each of the 4 corners of the audience area, it may be that the wind is still able to lift out all the fog with one good gust. And while you wait for the fog to come back, the crowd is commenting on how lousy the lasers look. Worst case the wind blows all the fog back on top of the band/DJ performing up front, pissing them off.

    This is why I say outdoor shows suck. To do them right you need lots of power in multiple locations and lots of fog/haze capacity, also in multiple locations. And you always have to be ready for the fact that at any moment the wind could blow all your fog away, making things look pathetic. (That's a good time to go dark on the lasers and rely on the regular lights!)

    When I've done outdoor shows I always have at least 4 sources of fog (and frequently I have 5 or 6). I always use multiple projectors. I always use as much power as I possibly can. And I do everything I can to control the location to minimize the impact of wind. As a last resort, if you can hang a screen somewhere you can always switch to graphics or abstracts if you can't keep the fog going.

    Adam

    PS: To your other questions regarding beam quality - as a general rule 1 watt is 1 watt. Some vendors fudge the numbers a bit, but on the whole they're pretty decent these days - even the ones from China. Note that ordering from China can create a problem with customs if you are in the US. And finally, displaying in the desert is going to be the most difficult challenge by far. Desert air has nothing in it to scatter the beam, so you *must* use fog or haze.

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    I typed a long response to this the other day and somehow lost it in the send process so, I'm glad buffo added something. My first comment was there is nothing "quite variable" about a variance. You either have one or you don't. The projector either has one or it doesn't. If you're in the US (and I'll assume you are, since you said variance) then you need a variance. I'm sure these parties are not totally free - no concession food being sold, no admission, no beverages for sale, no merch for sale - shirts/hats. It's a hell of a backyard get together for friends otherwise so... you need a variance and need varianced equipment which precludes you from getting "cheap Chinese".

    Also as has been said, you generally want to have a lot more power outdoors. My suggestion would be to use a green only projector since you'll get the most bang for your buck. Check with Walt Meador at Laser Rentals Inc and see what he's got in a 4 watt green. - Like this: http://www.lightspaceusa.com/starburst-green-4-000.html
    PM Sent...

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    Whilst the adage of 'more power is best' is true, in any laser gig situation, your beams are only as good as the quality of your atmosphere.
    I have a picture of an outdoor festival stage (I think it might be my banner pic on my page in my sig actually) I do annually with 4W, 8W and 20W projectors on it, and whilst you can see the difference between the 4W and 20W, its not as big as you'd expect.
    The common factor is that its consistently hazed, and you actually need very little haze to make even weak beams immediately visible.
    I've spent years doing 'collective' events in ad hoc outdoor locations, and for me part of the appeal is some of the abberations you get from the swirl of the wind through the trees. Consistent haze is boring and reminds you you're outside in the elements.
    So my advice is to buy some mid sized projectors 4-6W or so, and spend a chunk of any budget on some haze. Many small ones are better than 1 big one, but you want something that can run constantly, all night, and be somewhat frugal doing it (foggers running constantly will bankrupt you!)
    I've tried many solutions over the years and now just use Smoke Factory Tour Hazers or HazeBase Base Hazer Pro (basically the same unit in different configurations)
    They're not that cheap, but get the job done whilst sipping the fluid.
    All the other lights will benefit too. Otherwise you're just hoping for nature to be kind.
    One benefit of a bit of wind in the forests is it keeps small bits falling out of the trees, which the lasers will pick up, like woodland rain.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

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    Recently saw this video and may be useful to gauge the laser power needed in their conditions.

    My kit: Mamba Elements V3 & DAC, ILD SOS & LaserCam, LaserDock DAC, Kvant Clubmax 1800 (2017)

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    Quote Originally Posted by Melgarh View Post
    Recently saw this video and may be useful to gauge the laser power needed in their conditions.
    The general concept behind this video is a good one, and I applaud Kvant for taking the time to shoot the clip, but the conditions for the demonstration were quite favorable and this fact is not mentioned anywhere.

    At about 3 minutes into the video, when they are showing the beams with no haze in the air, if you look to the right in the background you can see a streetlight/houselight turn on. Look at how spread-out the light is, and how it has a soft halo of fog around it. My guess is that it was exceptionally humid the night this was filmed. Regardless, the fact that there was enough scattering medium present to give such a noticeable scattering effect to a non-coherent light source means that all the lasers in the video will appear brighter than they otherwise would.

    I don't think this was intentional on Kvant's part. (That is, I doubt they purposefully selected a humid location.) But the fact that conditions were unusually favorable when they shot the video should have been mentioned, in my opinion.

    The other issue I had with the video is the way the lasers were positioned more or less on the ground and then aimed up at a 30 degree angle. In this case, once the beams are more than about 50-75 ft up, there's no way the haze is going to have any further effect on visibility (since you can't keep haze contained that high up). So this has the effect of making the lower power projectors seem brighter when compared to the higher powered units.

    I feel a more realistic test would be to mount the lasers 12 to 15 ft off the ground and aim them at a more shallow projection angle - something like zero to 15 degrees above the horizon or so. This would have been closer to how the projectors would have actually been positioned if they were being used for a concert or festival and would have given the viewer a better sense of how the effect intensity falls off with distance from the source.

    Adam

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    I thought that was the moon Buffo.
    Notice that it dims and brightens too at various points which means the camera could be compensating for various levels of saturation.
    I agree though, the 'no fog' shots were incredibly favourable, especially as you could see the 'thickness' of the atmosphere.
    Lasers and rain are pretty damn magical too. I had the pleasure of working an outdoor forest event when we had a not too heavy shower around 3am and it was just immense. We turned off the haze for max droplet effect.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

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    Quote Originally Posted by norty303 View Post
    I thought that was the moon Buffo.
    I don't think so. The video had to have been shot over several hours, but the light is in more or less the same position (right above the trees) for the entire thing. If it were the moon, it would eventually rise higher or set completely. Either way it would be out of the frame.

    Notice that it dims and brightens too at various points which means the camera could be compensating for various levels of saturation.
    Which is another variable that affects the apparent brightness of the beams. Not saying that this completely invalidates things, but to be honest such inconsistencies should have at least been mentioned as a caveat...

    Lasers and rain are pretty damn magical too.
    Oh *HELL* yes! Rain is amazing. Snow is even better! But both are really rough on the projectors... I've actually had DPSS units fail to produce light due to cold temperatures. We had to go out and purchase heating blankets for the projectors to keep them warm enough to run properly!

    I had the pleasure of working an outdoor forest event when we had a not too heavy shower around 3am and it was just immense. We turned off the haze for max droplet effect.
    As long as nothing shorted out, that sounds like a great time!

    Adam

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    As long as nothing shorted out, that sounds like a great time!
    We live in the UK, everything has rain covers []
    Frikkin Lasers
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    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

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    Quote Originally Posted by buffo View Post
    I don't think so. The video had to have been shot over several hours, but the light is in more or less the same position (right above the trees) for the entire thing. If it were the moon, it would eventually rise higher or set completely.
    I believe your answer is the daytime view at 00:27. There is a concrete plant behind the field that they were shooting in. The light was on one of those structures.

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

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