askar c1 and c2 filters

[alacant]

Hi everyone
OSC with filters
c1: Ha OIII
c2: SII OIII

I made two stacks and extracted the Ha and SII respectively from each using Siril.
The OIII I made by combining the B and G channels from both stacks.
The registered and aligned files are here: https://drive.google.com/drive/folders/ ... drive_link

I then used Compose, SHO. The result is awful!

p1.jpg (406.05 KiB) Viewed 6660 times

Question: do we have a StarTools recipe for combining these duo filters?

Cheers, CS and TIA,
Steve

[hixx]

I assume You used a color cam and split the channels. From one stack You'll get: R= Ha and G/B = O3. From second stack You'll get: R= S2 and G/B = O3
A better way might be to do a third stack with images from both filters to increase integration time for O3= G &B channels to reduce noise
Then load S2 into R, Ha into G and O3 into B channel and have a play with the presets There are loads of them.....
Clear skies,
Jochen

[Mike in Rancho]

Hey Steve,

Short of time to check out the files, maybe on the weekend. Or a weekend after that lol...

But, you might consider ditching the B channel and only using G when creating the OIII file. Review the response graphs of your camera and the filters first, but for most OSC and duobands I think it should work fine. B can often be a weak and noisy edge, but the exact same structure usually falls through the filter bandpass and lands in the G. Frequently stronger, and of course you also have 2xG pixels. So, that OIII might end up cleaner when not averaging in the original captured B, especially if you are not using ST to bump the G's weight prior to extraction and combination. But sometimes even so.

Then of course your final OIII would typically be loaded into the B for your SHO in compose.

And when processing just play around with matrices as you see fit, along with the saturations, style, and LRGB emulation, as all can have strong effect on the resultant presentation.

Crescent could still "look" weird in SHO, as it is an object that we are maybe more used to seeing in bicolor. Or even RGB with Ha and OIII enhancements.

[alacant]

Thanks everyone. I really appreciate the time taken for your replies.
You've confirmed my suspicion that leaving B out of the stack may produce a cleaner result.
It gives me new hope that there is no correct or agreed way to do this stuff and that experimentation is what it's all about. Perfect.
Cheers and CS
Steve

[alacant]

I assume You used a color cam and split the channels. From one stack You'll get: R= Ha and G/B = O3. From second stack You'll get: R= S2 and G/B = O3
A better way might be to do a third stack with images from both filters to increase integration time for O3= G &B channels to reduce noise
Then load S2 into R, Ha into G and O3 into B channel and have a play with the presets There are loads of them.....
Clear skies,
Jochen

Thanks, yes. That's exactly what I did. Still thinking...
Cheers