M31

[astro mick]

Hi.

This image was taken during last week with my ED 80 and a Canon 1000D.

Its the sum of 25x 300 secs,calibrated with bias/darks and flats.

I see no blues or yellows that i see in other captures,so was wondering why that is so.

I did balance the RGB values in PS.

Thanks for looking.

Mick.

 

[tomato]

Hello Mick,

That's a nice shot, plenty of detail and you have it all in the frame, something which is not possible on my set up.

I had a very similar colour on this subject  when I equally balanced the RGB channels, I had to manipulate the colours quite a lot in Astro Pixel Processor to get the colours you describe, fortunately the APP RGB composite tool has simple sliders you can adjust with a fast update so you can home in on the desired result quite quickly, but I'm afraid that's not much help to you if you don't have APP.

Steve 

[astro mick]

Thanks Steve.

Appreciate the comment.

Interesting about APP though.

Mick.

[wimvb]

Nice image with good framing and detail.

Getting colour balance right can be difficult, especially if you image under light polluted skies. Each program has its own method for colour balancing. In PixInsight I would first neutralize the background, such that an eyedropper test would show equal values for R, G and B. Then I would correct the white balance by using the galaxy as a reference (average colour of the stars in most galaxies is white). This will almost allways result in warmer colours near the center, and cooler (bluer) colours towards the outer regions of a galaxy.

Here's what colour calibration in PixInsight made of your stretched image. Not good, because you need to do colour calibration on linear data, but definitely a variation in colour: