Transforming Monochrome Images into RGB with Ha, OIII, and SII. Pixelmath Magic in Siril.

Pixelmath Expression RGB (replace XXX with proportions)
qeSII = XXX
qeHa = XXX
qeOIII = XXX
R: max(max((0.2196*SII)/qeSII, (0.4510*Ha)/qeHa), (0.0078*OIII)/qeOIII)
G: max(max((0.0039*Ha)/qeHa, (0.9961*OIII)/qeOIII), (0.9373*(Ha*.25))/qeHa)
B: max(max((0.431*SII)/qeSII, (0.1216*Ha)/qeHa), max((0.8275*OIII)/qeOIII, (Ha*0.25)/qeHa))
Want to make monochrome narrowband images look like true RGB images? This past month, I captured the Orion Nebula with narrowband filters. In this video, I process those data using free software (Siril, Gimp and my sharpening tool), showing how I did it. My discord has the data if you'd like to follow along, or try to process it better than I did: / discord
Tim Hutchison's Presentation: www.youtube.co...
Doug from ‪@AstroAF‬ video on HDR Orion: • AstroAF - HDR Processi...
For those interested, here is the gear I use (or equivalent; Orion has discontinued some of their products, so the equivalent skywatcher products are listed). Most of the links are Amazon Affiliate links. Thanks!
Skywatcher HEQ5 Mount amzn.to/3NVrVQi
Skywatcher 80mm F7.5 Doublet amzn.to/47mbfZi
ZWO EFW mini filter wheel amzn.to/48OxhoN
Optolong LRGB Filter Set (1.25") amzn.to/47r23Tw
Orion 0.8x Reducer amzn.to/47s64a4
USB RJ45 Cable for Controlling Mount amzn.to/4aPlIzu
Raspberry Pi to control mount amzn.to/48mTBWH
R Pi case with touch screen amzn.to/3HvdNKl
ZWO Autofocuser amzn.to/3Skg0hX
Link to Siril: siril.org/
Link to Sirilic: gitlab.com/fre...
Link to Gimp: www.gimp.org/d...
Link to G'Mic: gmic.eu/downlo...
Link to AstroSharp/AstroClean: github.com/dee...
Link to Starnet: www.starnetast...
#astronomy #astrophotography #neuralnetwork #gimp #rstudio #photography #machinelearning #free #celestron #zwo
nqFI29h8W0Fp9UkKOJry

[@deepskydetail]

Pixelmath Expression RGB (replace XXX with proportions)
qeSII = XXX
qeHa = XXX
qeOIII = XXX
R: max(max((0.2196*SII)/qeSII, (0.4510*Ha)/qeHa), (0.0078*OIII)/qeOIII)
G: max(max((0.0039*Ha)/qeHa, (0.9961*OIII)/qeOIII), (0.9373*(Ha*.25))/qeHa)
B: max(max((0.431*SII)/qeSII, (0.1216*Ha)/qeHa), max((0.8275*OIII)/qeOIII, (Ha*0.25)/qeHa))
Tim Hutchison's Presentation: czcams.com/users/livecu76vNPq4Tc?si=Ev7g0NO2Ue35qLh3
Doug from @AstroAF video on HDR Orion: czcams.com/video/1eeHur-y0qE/video.html
Affiliate Links of my gear:
ZWO 294MM Pro Camera: bit.ly/3tZmjOo
HEQ5 Mount: bit.ly/3O7VQVz (mine is Orion Sirius, which is equivalent)
ZWO Filter Wheel: bit.ly/3Soo5lw
Optolong Filters (LRGB, SII, Ha, OIII): bit.ly/3SlEPtJ (the Ha and OIII narrowband filters are better than what I have)
Skywatcher Evostar 80mm: bit.ly/4bfVjev (equivalent lens)
USB RJ45 Cable: bit.ly/48FRj50 (connects mount to laptop directly; mine is a different brand, but this should do)
ZWO Autofocuser: bit.ly/425XUDB
0.8x Reducer: bit.ly/3tQlbg7 (mine is Orion, but this should be equivalent)

[@AstroAF]

Thanks for the shout out!! Isn’t a prerequisite to being into astrophotography that you have to be a bit weird? 😂
Excellent pixelmath demo and Great image Mark!
Cheers!
Doug

[@deepskydetail]

Thanks, Doug! It probably is a prerequisite 😅😂

[@Arcteek]

Brilliant video. Thank you so much

[@deepskydetail]

Thank you!

[@TevisC]

Nice. I leaned quite a bit

[@deepskywindow]

Nice video and technic! I wonder if that could be used to get better RGB stars from NB data 🤔

[@deepskydetail]

Yes, I think so! Whenever I use this technique, the stars look pretty natural (a lot of nice natural blue looking stars). But, that has just been my experience (so maybe I'm wrong). There is probably a way to incorporate just the stars into the Hubble palette too with masking/starnett++ etc. :)

[@PantherBlitz]

Is it a good idea to adjust for QE when using RGB filters too?

[@deepskydetail]

That's a good question! I don't know to be honest! But if you did it would be much harder to figure out because the RGB filters are broadband and aren't made for just one emission line... 🤷‍♂️