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Thanks guys,
The illuminated exposure was of 20 secs duration to bring out the glow. In the field, I guestimate the exposure time to be around 1 sec for Luminance and up to 10 secs for R G B flats based on previous experience.
I mostly take flats in the dark, so daylight light intrusion is not an issue, although thinking further, I reckon that placing a diffuser sheet in an empty solar filter cell would be a good alternative if you want to take flats at dawn or dusk; just point the OTA at a clear piece of blue skies with no clouds or gradient.
Seeing the LEDs through the bucket can also be useful to confirm that all 6 are firing, although as they are wired in series I guess that isn’t necessary; if one goes they won’t illuminate.
The main reason I guess for blackening the outside, is to avoid being thrown out of the observing paddock by the DOB owners and eye-ballers!
Cheers
Dennis
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