[graham.hobart (Graham stevens)]

Hello. Over last week and last night I collected 4.41 hours on Thors Helmet- LRGB.
The sub exposures are all 300sec each, the Luma bin 1x1, RGB bin 2x2.
I calibrated with flats darks and bias frames.
I stacked in Maxim using initially 1/1/1 ratios RGB then changed to 1/1/0.8 when I noticed it was so blue.
I used median combine then SD mask.
Both sets came out a deep blue background.
I enclose an unstretched frame then a blue frame that has just been cropped slightly then DD'd in Star Tools only, and finally a cropped processed frame in Star Tools -why is it so blue?
The only thing I can think of is one of the initial blue frames was actually bin 1x1 instead of 2x2 but that was only 300secs.
Help!
Graham