How much power do I need?

I am interested in purchasing a red or green laser system for displaying logo/text/animation. I am not interested in using this in an indoor setting, but outside to project onto abandoned buildings. Is there a guide or calculation to use to judge how powerful of a laser I will need at a specific wavelength and dispersion?

Let us say I want to project a simple image 200 feet wide, from 200 feet away, and have it highly visible at night from 500 feet away. How do I discover what this will take regarding laser needs? Do laser systems also include keystone adjustment?

speak to brewcitymagic, he works with stage lasers for a living.

500mW to 1000mW of green should do nicely..

^^ no chance, anything below 1watt is useless outside.

i would suggest a mnimum of 1watt green and to get a matching red you would need 3wattsd

You're right if you're needing a visible beam, but for graphics projected onto a building at night, 500mW to 1000mW of green should work great. I've used my 200mW green system with very good results on the side of a very large building and I could see the projection very well.. i don't think the OP needs visible beams (although it wouldn't hurt..) also, 1000mW = 1W..

ElektroFreak said:

You're right if you're needing a visible beam, but for graphics projected onto a building at night, 500mW to 1000mW of green should work great. I've used my 200mW green system with very good results on the side of a very large building and I could see the projection very well.. i don't think the OP needs visible beams (although it wouldn't hurt..) also, 1000mW = 1W..

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we may have to agree to disagree here

the beam on a 1watt green is not visible at night without smoke/fog.

i would not use any less than 1watt of green for projecting onto buildings.

I'm just going by my own experience, but I have no problem agreeing to disagree.

Whenever I post answers here, I assume the OP to be a person on a budget unless otherwise stated, so I always shoot out the most cost-effective advice I can. With lasers, it is possible to spend a nearly unlimited amount of cash but very few of us have it like that. A multi-watt green system is guaranteed to set the OP back a bit of money.. I'm only giving advice based on the fact that I have tried it before with 200mW and had no problem at all seeing the projection from more than 500ft away. Next time I do a building projection, I'll do it with my 200mW and film the results. It's not blinding, but it is quite easily visible.

If you can't see the beam from a 1W green outside with no fog or smoke, then it ain't a 1W green. I just received a 1W green module and it's like a freaking lightsaber, and that's in downtown St. Louis with TONS of light pollution. Of course, this is a motionless beam. In a scanner it will be less visible of course, but hardly invisible. I have a video of a 200mW green system (along with a 500mW RGB) being used outside with a small amount of mist in the air. You can see that the beam from the 200mW green scanner is EASILY visible with very little mist. This video was shot from ~175 feet. (ignore the crappy music)



After shooting this video, I felt like the standard conception that a TON of power is needed for outdoor beam shows might be a little excessive when you're not talking about professional shows. For amateur needs, I've been able to do OK with much less. The video proves that.

You're definitely right about the building projection in terms of getting the absolute best effect, but I'm firmly of the opinion that it could be done with less than a $2000+ expense.

I was thinking about this thread a moment ago and it occurred to me that this whole question is contingent on whether we're talking about being able to see the projection during the day.. If it needs to be visible in daylight, then a LOT of power will be necessary, like Andy said. It wouldn't hurt to have as much power as you can muster, regardless of day or night.

Would a high powered projector be more suited to xbsteve's needs?

IMO I think that you need a bit more juice then 1 watt.. i have seen 30 watt greens at a football statium.. they were pretty bright at around 200m away! but u will be less then half that distance.. i would go with 4-5 watts if you really want to go all out on this! you will see the image clearly with 1 watt but i honestly think you will be happier with 4-5 watts of green.. plus its a much better burner then 1 watt

just my $0.02

-Adrian

xbsteve said:

I am interested in purchasing a red or green laser system for displaying logo/text/animation. I am not interested in using this in an indoor setting, but outside to project onto abandoned buildings. Is there a guide or calculation to use to judge how powerful of a laser I will need at a specific wavelength and dispersion?

Let us say I want to project a simple image 200 feet wide, from 200 feet away, and have it highly visible at night from 500 feet away. How do I discover what this will take regarding laser needs? Do laser systems also include keystone adjustment?

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Usually you can adjust this in the software you are using to control the projector..

For a 4-5W system you're looking at ~$7,000-$10,000US depending on the brand you go with. There aren't really any budget options at those power levels. For that money, though, you'll be getting a very serious system. As far as brands, all I'll say is look seriously at a Kvant system if you have a good budget, and stay the hell away from Laserworld.

and have it highly visible at night from 500 feet away

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didn't see that before.. but yes 4-5 watts will do the trick!

You need at least 1 gigawatt if you want your lasers to go back in time.

carmangary said:

You need at least 1 gigawatt if you want your lasers to go back in time.

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Thanks for that.....:thinking:

The Pangolin FB3 package (And I would assume ALL the Pangolin packages) have keystone adjustment, yes. I would not be looking at any less than a watt for your purposes, but like many have said, more is better. You can get 3W greens from Laser-Wave that won't break the bank (In laser terms, not saying it's cheap )

Also, is money an object? Knowing your budget would help greatly ....

Seriously,

For a image of the size you need, and the distance you need, you are going to need a powerful laser with very low divergence.. Unless you expand the beam ( and loose scanner speed in the process ) your typical Chinese DPSS is not going to cut the cheese..

I would suggest you look at a 8w ( at least ) OPSL, maybe even combine 2 of them, and you are looking at some pretty serious cash now.