ETX TECHNICAL TIPS Last updated: 30 September 2003

Homemade Light Pollution Filter

Sent:	Monday, September 29, 2003 19:05:08
From:	rdhester2@earthlink.net (dan hester)
I had such good success with a wild idea that I thought you might want
to know about it.

Here in Wilmington, needless to say we have quite a bit of light
pollution. I happened to dig out an old Hoya glass uv filter for a 35mm
cam.  The box said the filter helped cut unwanted haze caused by
pollution and dirty air and give sharper pics....so...when I set up my
ETX 125 last night...I tried it.  I simply placed it over the
eyepiece... It wasn't my imagination...it did work!  I noticed quite a
contrast boost on Mars and the Moon.  So I got out my filter set and
took out a green filter that I could never seem to find a good use for. 
I took the filter out of the housing and hot-glued the larger uv filter
right on top of it. Then I got out my Wife's old glass grinder for her 
stained-glass projects and carefully cut the larger uv filter to the
exact size as the green one...inserted it into the filter housing...and
tonight..i tried it. I couldn't believe the difference...I guess its
somewhere between a  nebula and light-pollution filter.

I tried Mars with and without the filter...it was definately better with
the thing.  So was the moon...and messier objects stood out markedly
better than without the filter.  Maybe we don't need to pay 60-to-80
bucks for a little piece of glass...just go to your friendly photo shop
and pay 10 bucks...I bought a couple today at the local pawn shop for
five dollars each.

Happy seeing.  Dan

dan hester

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