[Aavso-photometry] Scattered Light

[bailyhill at aol.com]

HEllo



Oh Yea--I never waste good sky time doing flats, darks and bias'.  We do have the camera mounted permanently--and the temp compensated focus helps.  The software is setup so that it remembers from night to night where to go to achieve best focus, and the applies a correction for the temp.



\Clear skies

gary


-----Original Message-----
From: arne <arne at aavso.org>
To: Aavso-Photometry <aavso-photometry at mira.aavso.org>
Sent: Wed, 20 Jun 2007 8:04 pm
Subject: Re: [Aavso-photometry] Scattered Light




Greg Crawford wrote:
>If you do astronomy from Nantucket Island in the summer, it looks like you 
ave
>lots of cloudy nights to do long flats
 
 
 I'm puzzled by this idea of doing flats on cloudy nights. I would have thought
 it was necessary to focus immediately before taking flats in order to 
eproduce
 the optical configuration being measured by a flat; and that temperature and
 other changes would result in the scope being out of focus on those cloudy
 nights. 
 
f you have a permanent installation, so that you are not removing
he camera and having to refind focus every evening, you can get
close enough" on the focus to obtain good cloud flats.  However,
hat I meant in context with Gary and MMO, was that taking long
eries of dome flats is best reserved for a cloudy night so that
ou don't waste good sky time.
rne
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