Help with Laser Recommendations for Illustration on a Tennis Court

[Don]

I'm totally new to laser projection. I'm a few hours into reading up... but hey... I found this site so hopefully on track with my route to learning more.

I have a tennis training facility and want to be able to do laser illustrations on the court for instruction. I would write the software myself (professional developer).

I think I need to start my questions with safety. I'll obviously do lots of validation of what I learn here but can someone either head me off or give me a vote of confidence that I could develop a safe system to project onto the court. There would be players on the court and I'd need to have enough brightness that it would be compelling enough. It's an indoor court and is 78 x 27 feet with a 30 foot high ceiling. If it's a non-starter then why? I'd probably turn to a traditional projection system in that case... but I want to understand the issues well enough so that the laser projection idea is not hanging over my head if I go away from it.

Given a vote of confidence that I could come to a safe system... are there any specific systems that I should consider. I was thinking of something like an EtherDream DAC so that I could have a long Ethernet run to the ceiling to project down. But in terms of an ILDA laser projector I don't even know where to start. The inner court is blue with a green border. My first priority would be to project on the inner court area. Am I best to go with a single color for cost... and does a specific color help with safety. Would love the flexibility of RGB but can make trade-offs. I would ideally want to be sub 1K for a projector but would consider the project at multiples of that. I would be projecting things like targets, arrows, stats (text), etc.

Many thanks for any advice and recommendations you can give me.
Don

[Don]

Hmmm... from http://www.lasershowsafety.info/us-laws.html

I found this on audience scanning (which I think my application falls under)

Requires: 3) Use of low-intertia scanning devices such as galvanometer scanners (e.g., beam/graphic projectors) where multiple systems are used to detect scan failure and prevent exposure over the MPE.

Most of these methods require laser power meters to measure laser irradiance at the point of closest audience access. They may also require additional specialized equipment. The latter two methods also require effective scan-failure detection equipment.
The complexity of safely using scanning devices (items 2 and 3 above) limits their use to professional companies with special audience-scanning variances and projectors. Usually these are used for major tours, TV shows and other high-profile, high-budget projects

Not looking promising but would still like thoughts on this.

[dsli_jon]

Hi Don -

Welcome to PL.. Sorry no one seemed to latch onto helping you out with this, but.. Many folks are just way-oversaturated with 'life' these days (..I know I sure am.. ..but, let me offer some 'photons for thought'..

...There would be players on the court and I'd need to have enough brightness that it would be compelling... indoor court and is 78 x 27 feet with a 30 foot high ceiling. ...Would love the flexibility of RGB ..

Well, hmm.. I think it's not a question of *could* a projector be designed, to both achieve your goals, here, And be-safe - I am sure it could. There are, indeed, galvos (scanners) that quite likely could cover most, if not all, of the area you're looking to cover, especially since the 'content' seems to be pretty simple.. And, Green would definitely be the recommended Color of choice (..because you could still see it, while maintaining safe-levels of light, at the distances / angles you'd be talking, here) but..

..The safety-controls / Quality-level of the PJ-components needed *to* ensure safety - both from a 'compliance' standpoint, as well as (really, More importantly..) a real-world standpoint (ie: scanners that would not 'drift' / be likely to squirrel-out, genuine scan-fail system, inside, etc..) - would put your 'ideal cost', here, Totally in the, uh, 'round file'.. This:

I would ideally want to be sub 1K for a projector....

..I think is the 'deal breaker', more than anything.. You'd really need to be looking at Several $K, for a proper, US-legal - and Safe - system, to do this.. Some 'top-end', (quality-wise) audience-scan-capable systems are north of $20K (!) so.. 'Sub $1K' is just really not gonna cut it, I think you'll find..

..And, even so, I think it would be best to 'prove it out' (ie: hire a Professional Co. to 'real world test' all this, Before you committed to a purchase, etc..) because you would need to see how it would all Look / perform, given all the scan-angles vs height (your 'scan-envelope'..) vs the ambient-lighting conditions, vs the Player eye-safety, etc, etc.. Quite the Balance, I'd say - definitely something you'd want to 'pre-flight'.. And a Pro Co. would make that a (reasonably) affordable task, vs 'up and Go Buy it all'...

There are a few Pro Co's / individuals that are 'regulars', here in PL / up in your area, there, and I'm sure they'd be glad to help you look more into doing a 'proving test', to see if this would even all be worth investigating further.. But - just stepping back from this / looking at your 'hopes' for a budget-ceiling.. I think you'd be better off with (yikes, can't believe I'm saying this! a DLP video projector - or two - with a super-wide throw lens.. Even then, you're going to be into several $K, even 'used', methinks..

..Sorry to 'drop a turd into yer punch bowl' but.. Just my observations / food for thought.. Fwiw..

j

[mixedgas]

Don,

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Buy a 5 mW green OEM laser module from Z-Bolt, who are one of the few companies that still sell a low cost FDA compliant laser. Z-Bolt will meter the laser module's power for you. Tell them you want ~4.95 mW of green. They will understand why... You will need a 3.3 volt power supply at a few hundred mA to run the module. (Two D batteries in series will work). See what you can do with that dot, by hand, on your indoor court, under your lighting. This will put your device just into class IIIA laser safety. The Z Bolt module will need some mild heat-sinking to keep it stable.
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If you can see that dot on the court, and follow it when its moving, then you have a chance. If done properly, and your not combining the beams into one beam at the source, you can (in Theory) have as many of those as you like. I'll get into why in a later post, as I am busy trying to keep my job this morning.
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if you order a 5 mW Chinese laser pointer, there is no way these days it will ship at 5 mW and it might emit atrocious amounts of IR laser light with the green... Hence the pointer to Z-Bolt.
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1 grand is at the low end of this spectrum if you want any level of reliability in the scan hardware and controller... This has to work really well or your clients will find it to be an annoying gimmick...
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Link: http://www.greenlasermodules.com/BOL...er-module.html
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If Z-bolt doesn't float your boat, there is also Power Technology International, but the price will be much greater.
I've always been happy with Z-Bolt for CDRH compliant devices..
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It is possible to use a much higher power laser, but you need a professional like Jon or I trained in the techniques and math, and a scan fail safeguard... One with a minimum of five years experience and a ILDA or Laser Industry Association (LIA) Laser Safety Officer certificate. There is no legal requirement for your engineer to have the certificate, but it makes me feel better if you have a professional's help. We've had a spate of recent incidents of a person claiming to be an Engineer, pushing "eyesafe" devices that were well over the safety thresholds, by a factor of 100..
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There are maybe 100 people in the US with the right skill set for engineering a legal, safe, device..
Athletes and the general public on a tennis court expect a higher standard of safety then a club going teenager...
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The required power meter to ensure safety at manufacture costs 500-1000$, hence you need a professional who already has one..
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Or go to a very high end video projector with a lot of lumens, or a collimated arc light, both of which will be well above 1000$.
I guarantee you that you'd hate the arc source....
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Get back to me after you've tried a known 5 mW green source.. There are some folks up your way with the correct skill set and experience for this. The trick is to understand how much laser power you can have in a 7 mm eye pupil and for how long. Usually that is limited to class IIA (0.95 mW) or less, but there is a tightly worded exemption in the rules for alignment and training devices.
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Steve

[maxcady]

Whoa. Crucial rec on the Z-Bolt, and on a company that measures the power of it for you etc, this is exactly the kind of help I was hoping to find in my "safe green" laser thread!

This is awesome information, thank you.

[mixedgas]

Maxcady, Your reading too much into my post. I'm sending Don after a device he can use for a test. THE Z-BOLT Product is used for Class IIIA where a higher power laser is needed for certain tasks and is intended to be designed into a compliant laser product. It is not a laser show product that is eyesafe for audience scanning at point blank in a club. It is a reduced hazard device, not a eyesafe device.

STEVE

[maxcady]

I was excited to see a recommendation for a company that builds lasers to an exact power spec. In the other thread I learned that basically any laser you buy is not the spec that it says it is, and I've been wondering where to buy lasers that are the power they say they are, with no IR in the green. So this company seems like a good one to contact, right?

I'm not doing audience scanning at point blank, i'm not doing audience scanning at all. i'm adhering to the safety discussed in the other thread.

[mixedgas]

I was excited to see a recommendation for a company that builds lasers to an exact power spec. In the other thread I learned that basically any laser you buy is not the spec that it says it is, and I've been wondering where to buy lasers that are the power they say they are, with no IR in the green. So this company seems like a good one to contact, right?

I'm not doing audience scanning at point blank, i'm not doing audience scanning at all. i'm adhering to the safety discussed in the other thread.

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OK... If that is the case.......
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Z-Bolt is very good. But Class IIIA at 1.5 mm beam diameter is for occasional accidental exposures to a beam. For Don, it gets him an idea where he stands... Its something he can use because his lasers will be mounted high up and the person who accidently views it will have a contracted pupil due to daylight etc...
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One problem with the Z-Bolt devices is the stock model has no blanking at all. It must be mechanically shuttered...
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Steve