Project on water

[5mcmillions]

Is there any lasers that have the ability to project a 3’wide by 30’ long area on water? In daylight hours?

 

[LaserMicroscope]

Optically very challenging! When you project onto a screen, you’re using fairly well behaved reflection. Usually projection onto water requires projecting onto mist, as you must scatter the light and “hope” that enough photons make it back to your eyes to make out an image. Smoothly flowing or still water is simply too transparent to visible wavelengths for light hitting it to go much of anywhere but straight through.

 

[gazer101]

It depends on the water, if it is shallow then the laser will illuminate the floor and the scattered light will ruin your projection. If it is turbulent that will distort the projection. If you have deep and calm water, I'd say that a 1W green would work

 

[Cyparagon]

No. Quit talking out of your ass, gazer. You're wrong and here's why.

1W of green is about 600 lumens. Over an area of 3x30 feet, this is about 10 square meters. You're going to lose 90% of power into the water, so you have maybe 60 lumens across 10 square meters. That's 6 lux. That's assuming the surface is scattering light and not reflecting it, so it may be lower than 1 lux effectively. Y'know what the sun puts out by comparison? Well over 100,000 lux. And it's gonna glare off that water and over power the laser by several orders of magnitude.

No, Op. Describe your goal instead of throwing random specifications into the void.

 

[gazer101]

No. Quit talking out of your ass, gazer. You're wrong and here's why.

1W of green is about 600 lumens. Over an area of 3x30 feet, this is about 10 square meters. You're going to lose 90% of power into the water, so you have maybe 60 lumens across 10 square meters. That's 6 lux. That's assuming the surface is scattering light and not reflecting it, so it may be lower than 1 lux effectively. Y'know what the sun puts out by comparison? Well over 100,000 lux. And it's gonna glare off that water and over power the laser by several orders of magnitude.

No, Op. Describe your goal instead of throwing random specifications into the void.

I was referring to a laser projector that works by rapidly moving the beam using mirrors to create the illusion of an image (eg. https://m.wickedlasers.com/cube) as opposed to actually projecting the whole image at once. This puts the OPs request in the realm of possibility, but yeah you'd still need quite a bit of power...