RCC - Can't eliminate light swirls on M101

Request for feedback M101 Messier Objects Galaxy Deep Sky
3 replies•147 views
Glenn Silverman avatar
Glenn Silverman avatar

M101: Pinwheel Galaxy
I can't seem to clean up the light swirls and gradient anomalies in this image of M101, despite some aggressive work in GraXpert  and HT in Pixinsight. Is there anything else I can do or is this a problem in my image train?

Any help is appreciated.
Engaging
SemiPro avatar
SemiPro avatar
The data itself does not look that bad considering it came from San Francisco.

I think your first problem is a lack of certain calibration frames. Did you take darks? Flats? Flat darks or bias frames?

Did you do any colour calibration? After you remove the gradients, you can run background neutralization, and then some color calibration. Since you are using a OSC camera, you can use SCNR to remove some or all of the green depending on your tastes.
Helpful Concise
Jeffbax Velocicaptor avatar
Jeffbax Velocicaptor avatar
Hello. I think the main issue Comes from the flats. You should check them.

CS

JF
Glenn Silverman avatar
Glenn Silverman avatar
I took flats and biases for calibration. I think my flats may be off.
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