[Laser] filter response

[TWOSIG at aol.com]

I cannot tell you how they work, but I saw the pictures my late wife took in 
the 60's or 70's to test a haze filter for her 35mm camera.  We were standing 
on the beach on Padre Island on a partly cloudy day.  There was a lot of haze 
looking out over the Gulf.  I looked through the filter and could not see any 
difference in the amount of haze.  When the pictures came back the ones with 
the filter showed almost no haze, but the ones without showed the haze that I 
remembered.  I am pretty sure the film was for color prints.   I think she did 
a similar test on Black and White film.  I remember the dramatic difference 
between what I saw and what the camera recorded.

The description of the filter for a gun camera suggests to me that it was 
used by Navy aircraft at low altitudes.  I do not think that haze is as much of a 
problem in thin dry air.

You might try measuring the absorbtion of light from some red, yellow, green, 
blue (maybe white and ultra-violet) LEDs with and without the filters.  I 
would guess that the photo sensor should be fairly broad - maybe a CdS 
photoresistor.

Have fun.

James
N5GUI


In a message dated 6/14/2004 7:13:42 PM Central Standard Time, 
aflowers at frontiernet.net writes:
I found a bunch of "kodachrome haze filters".  The little yellow box 
says it is for a 35mm f/3.5 gun camera lens.  The instructions say that 
it is for taking picures on a hazy day when the light tends to be bluer. 
Anyone know what the filter response looks like?  The filter looks 
clear to my eye.

Andy K0SM