So e.g. Using the same data set on the pacman as in this earlier post.. and similarly with the bubble nebula
e.g. viewtopic.php?f=16&t=4741
The aim was to somehow combine a) RGB correct colour in stars, b) HA luminance for best detail plus star reduction and c) NB which provides the best and most informative nebula colour.
If anyone is interested ---- in PixInsight the process was
1) Process the RGB, O3 and HA through to the non-linear stretch stage
2) Calibrate the O3 image to the HA image (linear calibration process)
3) Use PixMath to build a HOO NBimage with 100% HA to RED, 100% O3 to GREEN, 10% HA plus 90% O3 to BLUE (this allowing for H beta and gamma)
4) Then use the PixMath Max function as max(NBimage, RGB image) to create a new NB image with correct colour RGB stars. Adjust the coefficients correctly and more or less just the stars will come over from the RGB image into the final combined image.
5) Then use LRGB to take the HA luminance into the NB/RGB combined image. This step reduces the stars and sharpens up the nebula detail
6) Then use Curves to adjust the luminance and Colour intensity curves.
Final results are much more highly coloured than with the previous RGBHa method. I think that the level of detail is similar but that there is now also clearer colour code information content on the localisation of OIII in the nebulae - as well as relative amount (e.g. really very little relative OIII to HA in the case of the bubble nebula - located only on and very close top the bubble itself; a significant amount of OIII located at the core and out to some of the fringes of the pacman). Main thing really though is that they look better
with best wishes to all for Christmas and New Year
TimH
