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Thread: New Here, Clueless, but have a vision - Underwater Projection

  1. #1
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    Default New Here, Clueless, but have a vision - Underwater Projection

    Dear All,

    Not sure where to get started so I'll jump right in. I have a public swimming pool and at night I would like to be able to stage a laser light show, even better still and my main motivation is to be able to do that in the pool underwater!

    I will try and read up on the available technology and threads here in the hope I don't dispel and disperse my idea.

    My Public Pool is on the Algarve, Portugal, it is 15x7x2m

    I look forward to connecting with some of you here and learning more about lasers, tech and shows

    For anyone interested this took place pre-covid, I hope it returns... https://www.facebook.com/luzafestival/

    Lee - PoolontheHill

  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    So here's the deal. When the laser beam passes from air into water, refraction causes the beam to bend away from the pool floor. A large amount of laser light will be reflected in random directions at the air-water interface from pool waves.. This results in a mess. It's generally just not done because a fully underwater laser projector is not cost effective nor off the shelf.

    Unless you have a very deep pool, it's not a great idea. Consider a water screen instead, but make sure pool guests cannot be sucked into the very large pump required.


    Sorry

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  3. #3
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    Quote Originally Posted by mixedgas View Post
    So here's the deal. When the laser beam passes from air into water, refraction causes the beam to bend away from the pool floor. A large amount of laser light will be reflected in random directions at the air-water interface from pool waves.. This results in a mess. It's generally just not done because a fully underwater laser projector is not cost effective nor off the shelf.

    Unless you have a very deep pool, it's not a great idea. Consider a water screen instead, but make sure pool guests cannot be sucked into the very large pump required.


    Sorry

    Steve

    Thanks Steve.... back to the drawing board - owe i'm already here ;-)

  4. #4
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    I once got to look through a window in the side of a university swimming pool from the air side. Mightn't a projector in such a gallery give some acceptable under water beam fan effects?

  5. #5
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    if he wants to try that, he could build a waterproof periscope with an AR coated window at the bottom. Remote the power and isolate
    supplies so high voltage doesn't kill any-one. Isolating the control system is going to be um, interesting.

    Pool wiring has strict codes around the world. Even a tiny leakage current can cause real problems for humans, especially children. Double insulation and full isolation are concepts required.

    The other downside is galvanic Corrosion.

    My other concern would be eye safety for swimmers. You know some kud, or some adult would want to ""see" the beam. That's "Aided Viewing" from a laser safety stand point. That's particularly dangerous.

    Sounds cool, but a regulatory and safety nightmare for a beginner.

    I love the water, I like the concept. But a one axis scan set with full termination on the pool wall sounds like a one trick pony, unless it's a vastly deep pool,and custom built.

    Not sure if Class IIIM [five milliwatts, thus reasonably safe] fishes and octopie scanned on thr pool floor are worth the effort.

    Dang, now I want to try it. Still a regulatory and safety nightmare.

    "Danger, Do not swim with beam in remaining eye"

    Steve











    Steve
    Last edited by mixedgas; 05-15-2024 at 01:04.
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  6. #6
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    Quote Originally Posted by mixedgas View Post
    if he wants to try that, he could build a waterproof periscope with an AR coated window at the bottom. Remote the power and isolate
    supplies so high voltage doesn't kill any-one. Isolating the control system is going to be um, interesting.

    Pool wiring has strict codes around the world. Even a tiny leakage current can cause real problems for humans, especially children. Double insulation and full isolation are concepts required.

    The other downside is galvanic Corrosion.

    My other concern would be eye safety for swimmers. You know some kud, or some adult would want to ""see" the beam. That's "Aided Viewing" from a laser safety stand point. That's particularly dangerous.

    Sounds cool, but a regulatory and safety nightmare for a beginner.

    I love the water, I like the concept. But a one axis scan set with full termination on the pool wall sounds like a one trick pony, unless it's a vastly deep pool,and custom built.

    Not sure if Class IIIM [five milliwatts, thus reasonably safe] fishes and octopie scanned on thr pool floor are worth the effort.

    Dang, now I want to try it. Still a regulatory and safety nightmare.

    "Danger, Do not swim with beam in remaining eye"

    Steve











    Steve
    you could use an led system underwater and project a gobo.

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