Description:Spatially coherent white light emerges from a slit, strikes the two halves of the biprism, and is recombined on the ground glass screen. The screen pattern, viewed with a minicam in the macro-zoom lens mode, is the same as two-slit white light interference: a white center flanked by colored fringes, with blue destructive interference closest to the center causing the complementary color to be seen, etc. A red filter can be inserted into the system to see more fringes, as shown above.