Flourescent Lenses

["David N. Horn" <dh@xxxxxxxxxxxxx>]

I noticed, about a year ago, that about half my lenses
flourese in UV light.
There seemed to be no correlation with lens age or quality.
It crossed my mind that lens flourscence, not film sensitivity
to UV, could be the main reason to use a UV filter.

Any ideas?

Dave Horn


>Date: Sun, 20 Sep 1998 22:05:24 -0500
>From: filje@xxxxxxxx (p j geller)
>Subject: uv&ir filters

>While using a black light bulb to
>look at some other things, I noticed that 
>a deep yellow glass filter was 
>fluorescing. I decided to check some other
>pieces of glass and found among the other
>things that glowed under uv were a B+W 092
>and hoya R(25a) , Y(k2), 
>but my older vivitar filters in ther
>same colors don't fluoresce
>except for  , a k2 med. yellow and fld.

>Another disturbing discovery was the
>first or second piece of glass shining brightly
>greenish-yellow in a  Canon 200 f2.8.
>as well as several other lenses.


>Would an IR image be sharper if there were
>a UV filter placed before an IR filtering lens?  



>phillip geller
>phillip geller photography
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