Tell me about the colour please.

[xelasnave]

I dont know what this is sorry to say or at least I lost my notes but I played with what I foundwhich must have been a deep sky stacker test...anyways how do you guys see the colour in a shot like this.
I played with it and guessed where the colour setting probably should be ...what is off?
Alex

[Atmos]

Apart from the background having a blue cast it looks like the star colours are correct. Some red stars and a smattering of blue ones.

[xelasnave]

Thanks Colin that is very helpful for me.
I processed that in gimp and will use those colour settings in future for the foreseeable future.
Have yet to buy pixinsite but just not getting many captures.
Alex

[LewisM]

I know what it is: NGC 2422 / M47.

ESO image of same so you can determine colours yourself: http://www.eso.org/public/images/eso1441a/

[RickS]

Alex,

If/when you do get PI, PhotometricColorCalibration works really well. The only choice then is how much to boost the saturation ;)

Cheers,
Rick.

[LewisM]

Rick, I've been using PCC, and always find a moderate green tint to all images after running it, and then need to use SCNR to remove that. Is this normal, or something to do with my light pollution?

I am setting a G2V reference star, and the parameters for plate solving, focal length etc are correct.

[RickS]

I've not seen that, Lewis. I have had problems when I didn't get the background fairly neutral before running PCC. I normally do that with DBE (or BGN if DBE is difficult to use on a busy field).

[LewisM]

I also pre-did it with DBE or BackgroundExtraction (not ABE) and one iteration of SCNR (green) just to be sure, and still get the green more often than not. Using SCNR again post PCC re-balances it.

[RickS]

Weird... wonder if it could be colour management settings, monitor calibration or something else external. I normally use average spiral as my white ref as I find G2V too reddish for my taste but I've never seen it produce a green tint. Is it an overall cast or just the background?

[LewisM]

Background. I recaled my monitor with Spyder again this week and still the same

[RickS]

Next time it happens I'm happy to take a look at the files if you upload them to Dropbox or somewhere similar.

[xelasnave]

Thank you Rick and thank you Lewis.
Alex