how can astrophotos be debayered?

[hjnet]

I do not get my photos of the ASI224MC in color, unfortunately I have to use Siril. Isn't that possible in Affinity?
Kind regards Harald

[James Ritson]

Hey @hjnet, this is when adding your files to the Light frames file list? Across on RAW Options, have you tried the FITS Bayer pattern option? It should be inferred from the metadata but we're finding this isn't the case with files from some setups and it defaults to Monochrome. I think the ASI224MC uses an RGGB pattern so try setting that.

Hope that helps!

[hjnet]

I've tried all of the patterns. Here is an example file.

Stack238_Light_Mond_2.0s_Bin1_gain300_20210220-205029_13C.fit

[James Ritson]

Ah, I see, that looks like a pre-stacked image, possibly from other software? I couldn't tell anything from the metadata.

Photo is expecting raw or calibrated frames to stack with. Have you tried any of your individual subs rather than a stacked result from other software?

[hjnet]

The stacked images come from the ASIAIR Pro Live Stacking. This function of the ASIAIR is actually very practical.

[hjnet]

Hello James,
thank you for looking at the stacked photo.
There are no problems with individual subs.
With the live stacking of ASIAIR Pro, you can see the result of the stacked photo right away.

Please excuse my english. That's all translated with google.

Kind regards Harald

[James Ritson]

Hi again Harald, no problem—the live stacking functionality is interesting, I was aware of it but hadn't seen any results. It would be more practical to be able to just open a singular FIT file within Photo rather than having to use the Astrophotography Stack Persona. I will chase this up as I think there may have been plans to implement it.

For now, however, I would recommend stacking with your individual subs and calibration frames—Photo will process everything in 32-bit floating point precision, whereas the FIT file you provided appears to just be 16-bit which may limit flexibility in post production (particularly with tone stretching).

Thanks again,
James

[hjnet]

Thank you for the information

[Noah Frere]

I also am having trouble stacking h-alpha. I can get 5 to stack, but if I stack 10,  they do not align correctly. I tried every setting I can think of in Affinity. Here is a solution that poster "Skylab" found, in the cloudynights forum: 

"This seems to be quite common.  I have troubles stacking my Ha images in PixInsight too.

At least in my case, the reason is that the strong noise in the green and blue channels (where there is almost no signal) interferes with the star-detection algorithm and leads to failures in registration.  (This seems to be your problem too, at least part of it.)  What I did to solve this is to ask PixInsight to use the super-pixel mode to deBayer, and then to extract the red channel of the deBayered color image.  The resultant gray-scale images stack very well.  This works because in the super-pixel mode, whatever in the green and blue will not contaminate the red.  (Bilinear deBayering should also have this property, but I did not try it.)"

Attached is a screenshot of my attempt at stacking ten raw files. BTW the OIII and non-filtered stacked fine. 

This makes sense to me, but I don't know if Affinity can extract the red channel and dismiss the others? -Noah Frere