Re: orange tint glasses (TECH3D digest 38)

[T3D Bob Howard <bobh@xxxxxxxxxxxxx>]

RE: John B wonders if any real worth..how is contrast increased etc.

Well, I guess in the '20s it must have been "Rose Tinted" glasses as 
there is some proverb or song? About looking at the world through 
rose tinted glasses. Meaning making it seem more wonderful than 
things are!
However, since yellow/green is the peak sensitivity of the eye. In 
fact achromatic lenses (the only correction in photo lenses that 
aren't apo's) came about because the early films were blue sensitive 
and the photographer was focusing his ground glass with yellow rays 
and hence pix were out of focus..so they saw the need to make blue 
and yellow-green coincide and let red shift for itself. (Latest glass 
brings in red too to near apo on best lenses.)
The yellow/orange will surely reduce any haze in the path due to 
scattering by dust/moisture etc. The orange (old Wratten G) filter 
was deemed to increase contrast when shooting wood products. Of 
course the extreme red filter makes contrast very high by eliminating 
shadow (skylight) illumination entirely, so orange yellow does this 
also to a lesser extent. BobH


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