Tuesday, December 1, 2009

Front Surface Mirrors

The heart of any kaleidoscope is the mirror assembly inside the holder. Actually, most any highly reflective surface could serve as a "mirror assembly" in a kaleidoscope -- e.g. a highly polished, reflective metal surface. 

However, nothing works quite as well as glass mirrors and, so, mirrors of varying quality are most widely used.   

When an ordinary mirror is used in a kaleidoscope, light must pass through a layer of glass before being reflected by the silvering on the back of the mirror. Since glass is not perfectly clear or perfectly flat, some attenuation of the image results, along with “ghost images” caused by reflection off of the surface of the glass. These undesirable effects are compounded in a kaleidoscope mirror assembly and cause the viewing field’s  outermost edges to dim, blur, and become full of interference lines.
By using aluminized front surface mirrors these problems are solved. Front surface mirror is made by vacuum depositing a highly reflective aluminum surface coating onto the FRONT of the glass. The light then reflects off the aluminized coating and does not pass through the glass. The high reflectivity (approximately 95%) and the absence of ghost images permits a brilliant image which remains clear and bright throughout the viewing field.  The resulting “hall of mirrors” effect results in images and colors that are much sharper and more intense that would be possible using ordinary mirror.    
To obtain that high quality image, I routinely use front surface mirrors in my scopes.    
To see my latest 'scopes and other work go to www.wrightmade.com     
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