shnkrmn
Well-Known Member
Telescopes and other precision instruments use front silvered or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have). Some of them use silver, but most are aluminum, which is more reflective at short wavelengths than silver. All of these coatings are easily damaged and require special handling. They reflect 90% to 95% of the incident light when new. The coatings are typically applied by vacuum deposition. A protective overcoat is usually applied before the mirror is removed from the vacuum, because the coating otherwise begins to corrode as soon as it is exposed to oxygen and humidity in the air. Front silvered mirrors have to be resurfaced occasionally to keep their quality.
So here are the best mirrors you can buy (not YOU, you can't afford them) and they reflect 90-95% when new.
Yes, this is from Wikipedia. Yes, it is accurate.
So here are the best mirrors you can buy (not YOU, you can't afford them) and they reflect 90-95% when new.
Yes, this is from Wikipedia. Yes, it is accurate.