My PixInsight Guide for Narrowband Bicolour Palette Combination

[kayronjm]

Read here: http://lightvortexastronomy.blogspot.com/2013/03/tutorial-nebulae-pixinsight-guide-for.html

The guide is not as extensive as my workflow tutorials and it's not meant to be. This guide only guides you on various ways you can combine your Hydrogen-Alpha and Oxygen-III (commonly the case) narrowband images into Bicolour Palette images, all in PixInsight. For more extensive instructions you can see my workflow tutorials but this guide can essentially produce the colour image for your post-processing.

[pfile]

just a question - should you do linearfit on the OIII against the Ha before the blend operation in order to get the pixel values roughly in the same ballpark? or are you already taking into account the relative weakness of the OIII in the pixelmath expressions?

[kayronjm]

just a question - should you do linearfit on the OIII against the Ha before the blend operation in order to get the pixel values roughly in the same ballpark? or are you already taking into account the relative weakness of the OIII in the pixelmath expressions?

Personally speaking I have not played around with the LinearFit function nor do I personally think of it as necessary for this but personal preference is personal preference!
I actually like having HA have a different intensity to OIII as this plays an important role in the colour distributions produced when combined. One can alter the balance a bit by altering the combination percentages such as mixing less HA and more OIII, or vice versa. This can take into account the relative signal strength. I also tend to alter exposure times during actual imaging (before post-processing) to produce desired results of signal strength for the various narrowband wavelengths.