What is the difference between a blue screen and green screen in movies?

Answer 1

the difference is actually just the color, you can use any color just as long as you key that color, you can choose it with the eyedropper in most programs, it just needs to be a color that is not used by anything that you dont want to be removed. so if someone in the shot has a blue shirt use the green color. i also heard that blue is better when shooting people because of skin tones.

Why Blue or Green? Can't other colors be used?
Red, green and blue channels have all been used, but blue has been favored for several reasons. Blue is the complementary color to flesh tone--since the most common color in most scenes is flesh tone, the opposite color is the logical choice to avoid conflicts. Historically, cameras and film have been most sensitive to blue light, although this is less true today.
Green has it's own advantages, beyond the obvious one of greater flexibility in matting with blue foreground objects. Green paint has greater reflectance than blue paint which can make matting easier. Also, video cameras are usually most sensitive in the green channel, and often have the best resolution and detail in that channel. A disadvantage is that green spill is almost always objectionable and obvious even in small amounts, wheras blue can sometimes slip by unnoticed.
Sometimes (usually) the background color reflects onto the foreground talent creating a slight blue tinge around the edges. This is known as blue spill. It doesn't look nearly as bad as green spill, which one would get from green.

Usually only one camera is used as the Chroma Key camera. This creates a problem on three camera sets; the other cameras can see the blue screen. The screen must be integrated into the set design, and it is easier to design around a bright sky blue than an intense green or red.

taken from http://www.seanet.com/~bradford/bluscrn.html

Answer 2

they're both used for replacing the background with other stuff. There isn't much difference except if you use a green screen, then you can't have anything green in the foreground... same with the blue screen. Green is the opposite of pink therefore it helps make sure that none of the human skin parts get keyed out.
Green spill (light reflected off the background onto the subject) looks worse than blue spill, so I would choose a blue screen... I use a green screen now.

Answer 3

It has to do with what kind of technology is used to add say a building without being at the building or something moving in the movie without really moving. A blue screen is used mainly for adding still images to the movie through computer technology and a green screen is used to anything that is a moving add on. it also has to do with what kind of computer programs that have to be used to do certain things for both moving and still back drops that have to be added a green screen works best.

Answer 4

Nothing, it can also be a grey screen or white screen or black screen. The computer afterwards knows to erase all of whatever colour it is told to, so in a green screen it would erase all the green colour, leaving the background (or whatever's being spliced on top) free for the effects guys to play with. However if the actor had a greenish top on that would be erased by the computer, so you need a different colour screen eg. blue so that it doesn't interfere with the actor's clothing or hair, etc.

Answer 5

The green screen is used to place images behind a performer to give the illusion that the performer is there. The blue screen is used to give the illusion that something that is there isn't. For example, to give the illusion that Gary Sinise, who played Lt. Dan in "Forrest Gump" had lost his legs, his real legs were covered in the same material as the blue screen, then computers place images over that to give the illusion that he was legless.

Answer 6

they both require different computer programs; if you are shooting on film and plan on doing the composite through traditional optical methods, you must shoot blue screen; if you are shooting DV Video, it is probably best to stick with green screen.

Answer 7

They both allow special effects to be added. Same thing.

Answer 8

They are different colors

Answer 9

None.

Answer 10

The color of it...