Home Depot Flat Light

Ideally you have clean optics and never need to use flats. However if you are unlucky, and have 20 years of internal dust motes like me, compensating with flats is important. I haven't had much luck with the t-shirt or white garbage bag and flashlight methods. My best flats were taken with the sky which doesn't help at night. I stumbled across round florescent lights at Home Depot and bought a 14" DIA to cover my C11 opening (approx 12.5"). I cut an old extension cord and connected it for power. The light weighs next to nothing but is very slippery and should be placed on top of the dew shield with the scope pointing up. For $40, my flat taking issues are solved and it doubles as a "clean up" light and the end of the night. Attached is a picture of the box. In the next post I will compare the flat field results

Regards,
Steve

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Using the Home Depot light required a faster web cam shutter speed to achieve approx the same brightness at f25. Both shots taken at 10fps for 15sec, processed identically with Registax4. You can see from the attached comparison that the light is at least as good as the sky flat. If you have a lot of dust, maybe this can help you.

Regards,
Steve

PS: For $600 Celestron has quoted me on recoating, shipping not included. Anyone know of people successful in cleaning/recoating?

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