Questions for NB imaging

[Ioannis Ioannou]

I'm doing my baby steps in tri-color NB imaging, I have some experience with Ha, but now I started shooting Oiii and Sii.
I needed to bin 2X2 both Oiii and Sii in order to get something in the limited time I had to image. A few advices please :

1) At which stage I should rescale them to match Ha ? I put everywhere (for Ha, Oiii and Sii) as reference image in StarAlignment the best image from Ha. The tool registered my frames and rescaled them. Does it really matter where I rescale them as soon as I do this when the images are linear ? Or I should first stack them and then rescale them ?

2) Which is the best workflow after ? use  LRGB, BackgroundCalibration, HistorgramTransformation and then the rest as I'm doing with RGB images ? or
Can I process each channel individually and then register-combine the non-linear results ? My concern is because I have uneven signal and noise on each channel. Ha is very good and needs just a touch of processing. Oiii has a lot of gradient and background noise and needs a lot of ACDR to get something proper. Sii has very low signal and needs a lot of stretch.

3) I understand that this is purely artistic-imaging, but how the heck people claim that they used HST pallete and they finished with nice blues and golds instead of greens and purples ? Playing with saturation? eg with CurvesTransformation and/or ColorSaturation ?  

Thank you in advance

[Nigel Ball]

John

I had the same problem when I first started I suggest you have a loot at these two threads

http://pixinsight.com/forum/index.php?topic=2346.0

http://pixinsight.com/forum/index.php?topic=2351.0

This first one has an excellent mini tutorial by Niall

HTH

Nigel

[Ioannis Ioannou]

Thank you Nigel, indeed Niall's mini tutorial seems very interesting regarding my third question.
But still I'm not sure about my first two questions.
Can I rescale the binned before stack them ?
And can I process each channel individually and then join while non-linear ? 

[Nigel Ball]

John

I dont bin my images even for OIII and SII so I cannot comment on this

As regards processing I process each channel to produce the best possible image for Ha, SII and OIII. I then combine the non linear images. The green image at the beginning of Nialls tutorial is such an image.

There are others on here that are far more experienced than I am and may be able to answer your questions more fully

HTH

Nigel