[pure-silver] Re: IR FILTERS
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 19 Feb 2011 14:44:50 -0800
----- Original Message -----
From: "BOB KISS" <bobkiss@xxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Saturday, February 19, 2011 12:20 PM
Subject: [pure-silver] IR FILTERS
DEAR LIST,
I recall a recent conversation about IR film
and black skies. A
few years ago someone also asked me to find the filters I
used for IR. I
finally uncovered them. They are:
1) Harrison and Harrison RD-10 (a.k.a. 88A) through
which you can see a
tiny bit of daylight. The directions say, "I.R. filter
absorbs visual below
710 mu).
2) Kodak Wratten 87C gel filter. Even if I look out as
the sun lit
tropical sky it is OPAQUE! To see the transmission
spectrum of the 87C
click http://www.beyondvisible.com/BV3-filter.html and
scroll down past the
UV filters to the IR filters.
CHEERS!
BOB
It would be interesting to use the 87C as a transmission
filter, its output would probably make things fluoresce.
--
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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