Blueshift - Wikipedia, the free encyclopedia
might be better than my explanation (the opposite of red shift)
IE when something moves away from you you will see it more in the red spectrum, but when it moves towards you its colours will shift blue. think of it like the doppler effect, when a car is traveling towards you , its sounds waves appear to have a higher frequency and as it passes you its sound waves have a lower frequency - nnnnnnnnnnneeeeeeeeeooooooouuuuuuuuuuuuu.
think of the colour waves like sound waves. hope that helps
Check it out the blue shift explained by my friend Zsolt. I think it covers all the info you may need about the white and all his properties. His website contains also some Precious info about tuning airbrushes, he's the man who fine tune the airbrushes for Marissa, lurk around his pages...
While white is usually listed as the culprit when discussing "blue shift", it's important to note that the "blue shift" phenomenon can occur anytime a light opaque paint is sprayed over a darker color...
To expound on Wicked's explanation, you can learn to use it to your advantage or add a bit of the color you are spraying over to the white to fool the eye into not seeing the blue shift.
That's sorta hard to do over black paint though. I've seen people do a light dusting of white over the whole surface so that you don't have the shift in just certain areas. If it's uniform over the entire surface your mind doesn't "see" it. If it's only in a spot or two then you eye will pick up on it and it'll be something that looks "out of whack" in your painting.
I try to preserve the blacks in a painting (if I'm painting over black) and try not to use white over sprayed black if I can help it. Vice versa with black, sometimes you'll get that nasty brownish shift when spraying black over white.
It's learning how to use a particular colors quirks to your advantage.
Wow so many definitions for the same term. As a photographer the term is used to describe how the shadows tend to take on a blue cast. In the absents of light more of the blue end of the spectrum is picked up. I suppose this could explain the white over black phenomenon, more of the blue spectrum is reflected back.