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ArcticMyst Security by Avery

Sanity check my idea for a RGV "liquid sky" effect.

Jun 10, 2014
A typical "liquid sky" effect is achieved by sweeping a laser beam across a flat plane, in the presence of smoke. (For reasons involving brightness and persistence of vision, rapidly sweeping a single beam works better than using a beam spreader / "line generator" lens.) The sweeping is usually done by shining a fixed laser on a rotating polygonal mirror.

I want to make this effect, but I also want it to seamlessly color cycle. I was thinking of using a dichroic mirror setup, like the white fusion kit, to combine all three beams and then sweep the combined beam, but then it occurred to me that I might not need to combine the beams. Since the effect already relies of persistence of vision, why not just aim the three beams in parallel at the mirror?

Would this work, or would the slight separation of the lasers create some problem I'm not forseeing?
Last edited:

Sep 12, 2007
That would mean each 2D cone of light would be projected in a slightly different direction - in proportion to its angle of incidence. In other words, the center of the 'sky' would be white, but the edges would have unavoidable color.