The only place where chroma key would help is a stationary flag getting partially obscured by a moving object. Otherwise, it’s more effective to just paste a drawing of all the hakenkreuze over each frame using decades-old subtitling technology. However, even stationary shots with non-moving flags (where the drawing can be reused) could be problematic because of picture jitter.
So what I meant was: the technique they would need was probably not chroma key.
For a stationary establishing shot, they probably could’ve pulled it off with paint on glass. Then just avoid shooting more than the bottom of the banners.
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If you check out the Wikipedia article for Chroma Key, it’s not as far fetched as you might think.
This is not chroma key.
It’s not - but not necessarily because the technology wasn’t there
The only place where chroma key would help is a stationary flag getting partially obscured by a moving object. Otherwise, it’s more effective to just paste a drawing of all the hakenkreuze over each frame using decades-old subtitling technology. However, even stationary shots with non-moving flags (where the drawing can be reused) could be problematic because of picture jitter.
So what I meant was: the technique they would need was probably not chroma key.
For a stationary establishing shot, they probably could’ve pulled it off with paint on glass. Then just avoid shooting more than the bottom of the banners.