"Yellow screen" mask generation using 589 nm sodium light

[rjlittlefield]

A recent video (April 7, 2024) was recommended to me by YouTube:

"This Invention Made Disney MILLIONS, but Then They LOST It!"

The title is clickbait, but the content is very interesting anyway.

What the video actually describes is a sort of "yellow screen" technique that is similar to green screen but uses the 589 nm narrow peak of a low-pressure sodium lamp, in combination with matching dichroic filters. Unlike conventional green or blue screen, which are wide bandwidth methods, the sodium yellow technique can handle subjects with virtually any colors, without significantly degrading either the alpha mask or the subject colors.

Disney used this technique for their early live-action animations, then switched over to blue screen and green screen because of cost.

I have no idea whether some variation on this technique might be useful to our community.

-Rik

[MarkSturtevant]

Very cool! I don't know of a specific application other than replacing the background of staged subjects.