Quote:
|
Originally Posted by NoWhErE
The reason why they use blue and green screens is for the simple fact that those 2 colours are the least dominant on a person's skin and in nature.
When performing greenscreen, you're telling the computer to eliminate a certain color from the image, well, if you were to use a white backdrop, everything that is white (including glares, eyeballs, teeth, etc) would be taken out of the image.
But green and blue are less likely to be found in images (especially the blue and green they use), so you have less chances of unwanted artifacts being lost.
Its that simple
|
Actually it has little to do with dominant colours and nature. green is everywhere in nature in fact it is the dominant colour. you need to get out of the city a little.
Red tends to bleed very badly so generally its avoided.
The eye is MOST sensitive to Blue. so video compression schemes throw away (compress) a lot of the blue in an image. This makes it a very poor candidate for chromakeying.
That leaves green as the only real choice left.
I wish I had known this a while back. Wasted hours of footage using a blue screen
I have seen a fantastic product which is a cloth made of small glass beads. it reflects green light. the camera is then fitted with special LED's around the lense which illuminate the cloth and nothing else. the result is near perfect chromakeying.
I cant recall what the product was called but it wasnt cheap.
A quick search failed to find it. but its out there somewhere
Ooops found it. Chromatte!
http://www.reflecmedia.com/content.a...=chromatte.htm
-