Kurt, try this approach: http://www.electrolamp.com/elpanel.html This particular site lists material with an odd voltage (but low current consumption, a power supply run from a car battery would be easy), but I know that it is made to operate from low DC voltages as well. You could make a light source as small as a dust cover that fits over the aperture, no more than an inch or so thick, and completely evenly illuminated. In fact it could double as a dust cap. If you can find the low-voltage material you could even dispense with the power supply. If made like this it wouldn't be a problem for even an observer right next to you, you'd leak no light at all. This thin sheet material can even be cut to odd sizes (like round), as long as you don't cut-off the power contact areas. The samples I have seen are about as thick as two or three document protector sheets pressed together. 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. Some of the low-voltage material changes color as you vary the voltage.
From: Canopus56 <canopus56@yahoo.com> Subject: Re: [Utah-astronomy] Flat Field Frames I'm new to this myself but happen to be in the middle of building a white light box, this evening in fact.
Twilight is fine, but what happens when you arrive after dark?
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