Quote Originally Posted by stickygreenlightsabr
Yes, the mirror WILL reflect more light. I'm not talking about diffused or focused, just LIGHT as in photons. Re-read the original post. If that wasn't the case, then telescopes would use something else.
Incorrect; at best, incomplete. A typically second-surface (silvered on the back of the glass) wall mirror has a reflectivity of approximately 85-90%, at maximum, because the glass absorbs a significant fraction of the incident light before it ever reaches the reflective surface, and absorbs the same fraction again on its way back out. Some high-quality white papers have reflectivities on the order of 90-95%. Telescopes and other precision optics use first-surface mirrors, to attain reflectivities greater than 98%.