A framed covering for an architectural opening includes a collapsible shade that is moveable between open and closed positions relative to the architectural opening with the collapsible shade being mounted within an enclosed framework that is adapted to be secured to a structural member having the architectural opening therein. An SNR setpoint is first calculated where such setpoint is based on the SNR setpoint of the associated primary channel and system offset values. The optical elements are preferably planar mirrors simultaneously fabricated from a wafer.