Natural background or light pollution

[Scooot]

I've taken a stack of images of the Arrow in Sagitta and dumbell using a CLS clip filter with an unmodded Canon DSLR 450D, 42 minutes worth of 30 seconds at ISO400, f4, with a 135mm lens.

The first of the attached is an STF autostretch of the stack after DBE.
The second is an STF of the stack after DBE,BN, colour calibrating, SCNR and a little noise reduction with MLT.

The background shows areas of deep reddish brown.
Are these areas of gas or nebula showing up as reddish brown because of light pollution which I should attempt to darken or blacken with further processing after stretching the image. Or should I keep it as a natural part of the image.

Thanks for any comments.

[John_Gill]

Hi,

I have looked at a number of images in the same area and some show "red nebula" in the area and others don't show anything.   The red could be caused by atmospheric conditions like pollution, high cloud and light.  Personally I would process the image with the "red nebula".

Look up
John

[Scooot]

Ah Ok.

Thanks for the reply John, much appreciated.