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View Full Version : what's the difference between blue screen and green screen, don't say "the color" ;-)


PIXAR
05-13-2002, 01:21 AM
what is the main difference in blue and greenscreen? it used to be always blue, but i have noticed that almost everybody used green these days.

I want to buy such a big piece of cloth, but what green is it, is it any special. Maybe de green has a number or something (like pantone colors, rgb values, you know)

thx!

levin
05-13-2002, 02:11 AM
not much of a compositing genius but... if one the elements has a deep blue color perhaps?

septi
05-13-2002, 06:48 PM
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.

PIXAR
05-13-2002, 08:06 PM
thanks for the replies!

yair
05-14-2002, 11:31 AM
Why Blue? 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

3DMadness
05-14-2002, 12:41 PM
It's interesting to watch the making of Hollow Man, just rent the DVD and watch the extra features. You will see that they choose different colors in different situations. Kevin Bacon used both green and blue cloth but also a black cloth when there was a wet environment because the water was reflecting the green and the blue of Kevin Bacon's cloth. :)
Just my $0.02 ;)

3D Madness

ilasolomon
05-15-2002, 12:27 AM
hey YAIR...that was great, useful, thank you...

ila

yair
05-15-2002, 04:02 PM
peace on us all

ilasolomon
05-15-2002, 09:58 PM
peace...& salute
feel free to visit my homepage, you'r welcome (anybody else too)

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