Puzzled about Ha stacks in PixInsight

[BrendanC]

Hi all,

I'm puzzled about stacking Ha subs in PixInsight.

If I stack them in APP or Siril, both of which have explicit 'Ha' algorithms/methods/options/settings, I get decent results (in fact I prefer Siril which is oddddd).

If I stack using WBPP in PI, with or without CFA debayering, it's a bit pants.

Here are quick examples of what I'm getting, viewed through ASIView which applies a gentle stretch to the FITS files.

So, my main question is: when stacking Ha in PI using WBPP, is there any specific thing I should be setting/ticking/activating/switching on or off to get a better result?

And my supplementary question is: would you like to see the stacks, so you know what I mean? If so, they're here: https://1drv.ms/u/s!AqovBuVZMwj3lesjCGJLmfm8D_argw?e=MuELbM  - about 200MB worth of FITS files. They're all of SH2-198 which is itself a slightly pants object but I had to go with what I could last night.

Thanks, Brendan

[BrendanC]

POST-EDIT: The solution is to Extract channels, then just take the red. I guess that's essentially what the Siril and APP settings do, it's just a quick extra step in PI (isn't that always the case...)