Laser light shows have ... this homebrew X-Y laser projector. This is actually [Stanley]’s second pass at a stepper-based DIY projector; we featured his previous build back in 2016.

Thanks to its triple-laser system, it’s able to reproduce “pure red, green, and blue light ... from the wall. There’s no 4K capability here – unlike Optoma's other new projector, the ...

First, to build your ... gain (how much light the screen reflects back). Therefore, would it be cheaper to tack up a white bedsheet to your wall rather than pay for a premium projector screen?