| moviePig wrote: Quote:Yes, the red filter *does* block blue... and the blue, red (...except for the leakage inherent in all systems: red/blue, polaroid, or shutter-glasses). When you say that "what gets through" merely appears as dark, that is in fact the effect of its having been blocked. Since my last post I have realized that you are right about part of this and I was wrong. The red filter does indeed block out blue light, and it is the fact that none of it gets through that allows the image that was projected and reflected in blue to be perceived by the eye behind the red filter. And likewise for the other eye, the blue filter, and the red projected image. But my essential point remains. The red filter washes out the red projected image, and presents the other image to the eye behind the red filter. The blue filter washes out the blue projected image, and presents the other image to the eye behind the blue filter. Quote:Take your two pairs of glasses and put a (single) lens from one against a lens from the other... and then look through the sandwich. If you've chosen opposite colors, the light that gets through will be greatly diminished, i.e., blocked. I don't have to actually do it to see that it is true. But so what? In the past I have done the same thing with polorized filters, and seen that when the polorization is at right angles, little or no light can get through the sandwich. Big deal. This looks like another red herring. |