[AZ-Observing] Re: Flats and Bias
- From: Jeff Hopkins <phxjeff@xxxxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Sun, 15 Jul 2007 11:07:29 -0700
Hello Stan,
You can indeed take flats during daylight. The problem is getting the
illumination down to a value you can use. The larger the telescope
the harder it is. Another problem is unless you have the optics all
set, focused and such, you will need to wait until you get things set
and that may mean after dark. You could go ahead and observe all
night and take the flats the next day, but I am too old for that. :-)
A light box offers the convenience of being able to take flats
anytime you want. Plus you can make it so you can adjust the
brightness.
Jeff
At 11:04 -0700 07/15/2007, Stan Gorodenski wrote:
>It just occurred to me, why not take a flat during the daylight? One
>would have to reduce the light coming in, maybe with a mylar solar
>filter. Does the sun in the sky create too much of a flux gradient
>across the chip no matter where you might take a flat in the sky? There
>obviously is a problem with this method since it does not seem to be
>mentioned in the sources I read.
>Stan
--
Jeff Hopkins
HPO SOFT
Counting Photons
http://www.hposoft.com/Astro/astro.html
Hopkins Phoenix Observatory
7812 West Clayton Drive
Phoenix, Arizona 85033-2439 U.S.A.
(623)849-5889
(623) 247-1190 (Fax)
www.hposoft.com
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