Author Topic: Flats issue - anyone care to check my data?  (Read 239 times)

Offline macnmotion

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Flats issue - anyone care to check my data?
« on: 2019 January 18 05:27:54 »

For the first time, we're having trouble with flats. We recently tried using sky flats. We don't have a convenient way to shoot illuminated flats for our 600mm scope, so we thought we'd try sky flats. It isn't easy to capture sky flats at our location (13.7N), the sky brightness changes very quickly. We are able to capture 5 or 6 flats only in the 23000-30000 ADU range.

Our system:

OS RiLA 600mm f/5.0
FLI ML16200

I can't get the flats to work at all. On one previous image this season using the flats, I was able to add a .20 pedestal to the master flat and it worked well enough. But in our latest images the flats aren't working. In fact, playing with various pedestal values, I can reach a point where I have dust motes both over and under corrected at the same time.

I've placed a subset of our data online  (flats, bias, darks, L). Can anyone take a look and tell me if there is some technical problem with any of the calibration frames?

Thanks. Andy