There are also a couple other little complications that may or may not apply to anyone here: 1. If you are doing photometry, your light box needs to have a "broadband white light" type spectra. I.e. LED's can give you trouble because they are much stronger at specific spectral lines. 2. If you use an SCT with a dew shield or some other telescope where you have a dew shield, etc. - you need to place the light box over the dew shield. Otherwise, you've modified the optical train and your flat frame might have some "issues". Clear skies, Dale.

-----Original Message----- From: utah-astronomy-bounces+dale.hooper=sdl.usu.edu@mailman.xmission.com [mailto:utah-astronomy- bounces+dale.hooper=sdl.usu.edu@mailman.xmission.com] On Behalf Of Canopus56 Sent: Tuesday, November 22, 2005 1:06 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Re: Flat Field Frames

--- Chuck Hards <chuckhards@yahoo.com> wrote:

...

Kurt, try this approach: http://www.electrolamp.com/elpanel.html

Thanks for referral. I didn't see any prices on the Epanel.

On the other hand, Patrick's piece of white board with a low flux light seems pretty simple and low-tech.

<snip>

...

I've often thought about using the red material and lining the edge of my eyepiece and accessory cases with a strip of it, or making a chart illuminator from it.

I hadn't thought of that alternate use for white field box. A simple piece of Roscolux #83 diffuse or #27 red cut to shape and held between two pieces of black artist foam board should do the trick.

I was also thinking about trying to use the white light box for holographic collimination of a Newt's secondary mirror. It would be the white light box with a piece of clear plastic printed with a 1/4" grid. http://web.telia.com/~u41105032/holographic/holographic.htm

- Canopus56

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