The translucent mirror patents.

If you were ever curious about the detailed specs of that so called “translucent mirror” used for SLT cameras than just take a look a Patent Number 8313254 (via freepatentsonline). It explains the material used and the reflective characteristics of the mirror: “the light-beam splitting mirror has spectral characteristics including a reflectivity of 25% or more and 35% or less at all wavelengths from 400 to 650 nm and a reflectivity of 60% or more at a wavelength of 700 nm”

Have fun reading all these tech!