Processing Flats problem

Dasidius

New member
Mar 31, 2020
4
0
Hello guys I have an issue that I can seem to resolve. When I process my picture using weighted batch pre-processing I'm getting large white gradients around the edges of my master light. The issue started when I switched to the Optolong L-Pro Filter filter for galaxy season. I have retaken all my bias, flats and dark's with the new filter. My equipment I'm imaging with is the ZWO ASI294MC Pro With a Hyperstar V4 on a C8 scope. I shoot all my shots at -10c, gain 120 and offset zero. My exposure times are five minutes. My target value I'm using for my flats is 25k ADU. I take my bias and dark's both at -10c. I use Sequence generator Pro to capture all my pictures and calibration files. I get this error message when I run batch pre- processing. **Warning: Only master bias will be used to calibrate flat frames (filter = noFilter, Binning = 1, exposure = 0.01s, Length =8) I have tried everything I can think of. Any ideas on what I can do different?
 

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bulrichl

Well-known member
Nov 2, 2016
692
34
La Palma, Canary Islands
There is one detail in your description that might be the culprit: offset 0. The default offset for the ASI294 MC Pro is 30.

Please check one of the calibrated light frames (captured with the multiband filter) with ImageStatistics ('Unclipped' unchecked; the value of 'count (%)' shall be near 100 %) and HistogramTransformation (with horizontal zoom, about 50, in order to check the low range of intensities): are the calibrated light frames clipped?

If this is not the cause of the trouble, there is something else that I cannot find out from your description.

Bernd
 

Dasidius

New member
Mar 31, 2020
4
0
There is one detail in your description that might be the culprit: offset 0. The default offset for the ASI294 MC Pro is 30.

Please check one of the calibrated light frames (captured with the multiband filter) with ImageStatistics ('Unclipped' unchecked; the value of 'count (%)' shall be near 100 %) and HistogramTransformation (with horizontal zoom, about 50, in order to check the low range of intensities): are the calibrated light frames clipped?

If this is not the cause of the trouble, there is something else that I cannot find out from your description.

Bernd
Thanks for the tip on offset, I was not aware of that and will change it ASAP. Where do I find the ImgaeStatistics at?
 

bulrichl

Well-known member
Nov 2, 2016
692
34
La Palma, Canary Islands
No, obviously the offset isn't the problem. If you want to upload a light, flat, bias and dark frame in FITS format and your MasterFlat, MasterBias and MasterDark in XISF format I can take a look at it.

Bernd