[APML]: Comet / Lunar light pollution - a semi-fix?

["Tom Krajci" <krajcit@det5wg57.barksdale.af.mil>]

A possible technique?

Comet Hale-Bopp is coming and it's gonna be fairly bright.  I'd like 
to be able to shoot it during times of moonlight and maybe I can use 
the trick daylight photographers use. . .darken the sky with a 
polarizer.

When the moon is 90 degrees from the comet the effect will be 
greatest but will probably also work on angles of 70 to 110 degrees.  
Sure the moonlight makes the sky background many, many times brighter 
than a moonles night. . .but you may get a factor of four (maybe 
more?) improvement with a polarizer and what's best - you don't 
change the color balance!

This spring I looked at Hyakutake through binoc's and played with a 
polarizing filter to get a rough idea of how polarized a comet's tail 
and coma are.  I couldn't see any brightness changes as I rotated the 
filter so I'd say comet features aren't very polarized, if at all.

Printing these photos?  Well, moonlight would make the sky background 
blue, just like reflected sunlight.  It's just so faint that we don't 
see that visually in color.  At least I don't.

Has anyone tried this technique?  If the @#$! weather would cooperate 
I would!

Any and all comments are welcome.

Tom Krajci
B-52 Intelligence Officer
http://spur.barksdale.af.mil