Why do you want to shoot with a green background or a blue background in film and television dramas?

I have seen the actual situation of many large-scale declassified films and lamented the advanced computer technology. I found that most of them were shot in Green's studio. Why?

Nowadays, movies, especially sci-fi movies, are mostly made in the later stage, which requires people to be cut out and put in the background. In the later stage of film and television production, you can change the background, mainly by using the chroma key, and then use this chroma key to cut the picture. With the new background, it is easy to cut the picture into three primary colors. However, because people's skin is close to red and yellow, red is basically not needed, and blue and green chroma keys are just fine.

In addition, the brightness of green background is higher than that of blue background, which is also an important factor for lighting engineers. Early keying was also often shot on a blue background.

You see, in this photo, it is green. It is very important that captain America's clothes are blue ~

However, Scarlett uses blue, but my widowed sister's eyes are a little blue ~

Keying principle should be supplemented by other processing of keying.

The core of keying is to obtain the complete alpha channel of the object, so the most important thing is actually the edge part of the object! ! ! For example, hair, translucent skirts, screens, etc., this keying requires the highest smoothness and saturation of the background. There are also translucent parts such as glass refraction.

For foreigners with blue or green eyes, it is actually very easy to deal with. Generally, you just need to do a mask tracking, and the edges of the object are all handled.