alt Hacker NewsFrom ~04:10 till 05:00 they talk about sodium-vapor lights and how Disney has the exclusive rights to use it. From what I read the knowledge on how to make them is a trade secret, so it's not patented. Seems weird that it would be hard to recreate something from the 1950's.
I also wonder how many hours were wasted by people who had to use inferior technology because Disney kept it secret. Cutting out animals and objects from the background 1 frame at a time seems so mindnumbingly boring.
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It is a well known process, Not a lot of general use so costs are not low, but not nearly as high as the original disney prism, I would guess around a 1000 USD for one. As far as I can tell any well equipped optics laboratory could make a beam splitter with whatever frequency gate they want.
https://accucoatinc.com/technical-notes/beamsplitter-coating...
I have no idea about that specific company I just picked it after a search for "beam splitter"
After I saw that video on the sodium vapor illumination process I was curious as to what if you could instead use near-IR light as the mask illumination. In theory you would have a perfect mask(as in the disney process) and no color interference. I found that frequency gated beam splitters are a fairly common scientific instrument.
Yeah, that's just nonsense. We used sodium vapor monochromatic bulbs in my high school physics class to duplicate the double slit experiment.
I suspect the real reason is that digital green screen in the hands of experienced people is "good enough" vs the complication of needing a double camera and beam splitting prism rig and such.
Even if it had been patented, patents from the 1950s would have long expired. In fact, patents from 2005 would have expired - the US patent term is only 20 years.
The lights are relatively easy to get. iirc (it's been a bit since I watched their full video on the subject[1]) the hard part to find was the splitter that sends the sodium-vapor light to one camera and everything else to another camera.
1. https://www.youtube.com/watch?v=UQuIVsNzqDk