Spoilers Possible [major spoiler] in Picard season finale
- Thread starter urbandk
- Start date
It depends on a number if factors. Lightning is one, depending on the needs, as well as primary color of the environment or item being filmed.
Not really, no. Those colors are used because they are the way color is "read" by a camera, since cameras use Red, Green, and Blue (RGB) channels. Using one of those as pure color allows it to be tracked and replaced more easily.
If you want an example of what can happen with a blue object and a blue screen look at R2's panels in Star Wars Episode 4's trench run. His panels look black in the space scenes due to the use of blue screen and replacing the background for space. In the process, the color of his panels was replaced as well.
So, if the primary color of the object you are filming is blue then you are going to want a green or red screen.
Now, this is all my own understanding of it. I'm sure someone who actually works in the industry, rather than just doing fan films with friends, could inform you even better.
The way I heard it was if they had left R2 as blue you would have been able to see the background of the death star and other ships through R2s panels. Therefore they painted R2s panels black for those scenes in order to prevent the blue screen error.
There are ways to ensure that the middle of objects aren’t matted out even with colour clash.
Most TV cameras emit three signals, Y, then two Colour difference signals (CrCb), which is analogous to “YUV”, with the CrCb channels using half the sampling (so 4:2:2).
In the olden analog days chroma key cameras used to 4:4:4 into the keyer
HDR has changed the colour space somewhat, I’m not entirely sure how, and digital cinema and high end production on something like a Red camera may be different (my experience is with low end stuff on news)
I haven’t personally seen a blue screen in my career - plenty of green screens in the early days but they’re rarer now (I’ve replaced a lot with 60-80” flat screens). How’ve the places I’ve seen them are in news studios which are well lit and fixed sets, somewhat different to dramas.
Chroma key for backgrounds were hard to calibrate well, especially to work in generic cases. I remember broadcasting a disastrous looking interview with an army person once, with his uniform, tie, hair and glasses all conspiring, part of the reason we use tv backgrounds now, but again that works fine for news/weather but not for special effects.
Most TV cameras emit three signals, Y, then two Colour difference signals (CrCb), which is analogous to “YUV”, with the CrCb channels using half the sampling (so 4:2:2).
In the olden analog days chroma key cameras used to 4:4:4 into the keyer
HDR has changed the colour space somewhat, I’m not entirely sure how, and digital cinema and high end production on something like a Red camera may be different (my experience is with low end stuff on news)
I haven’t personally seen a blue screen in my career - plenty of green screens in the early days but they’re rarer now (I’ve replaced a lot with 60-80” flat screens). How’ve the places I’ve seen them are in news studios which are well lit and fixed sets, somewhat different to dramas.
Chroma key for backgrounds were hard to calibrate well, especially to work in generic cases. I remember broadcasting a disastrous looking interview with an army person once, with his uniform, tie, hair and glasses all conspiring, part of the reason we use tv backgrounds now, but again that works fine for news/weather but not for special effects.
Oh. Interesting. I hadn't heard that.
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