ASI533MC - Siril stacks have colour, DSS and APP do not

[BrendanC]

Hi all,

So, I recently took a step back from mono to OSC - a nice little ASI533MC Pro.

I've just used it for the first time tonight, and after doing a test stack in APP, when I bring the FITS file into StarTools, it's only giving me the option for a Linear or Non-Linear image - that is, no OSC option. Processing it then proves that there is no colour information.

Same with DSS stacks.

However, with Siril, after stacking as an RGB image, I do get the OSC option and can process fine.

So I'm sort of OK for now with Siril, but would like to understand why APP and DSS aren't playing ball.

Any ideas? I know this is not strictly a StarTools issue but if anyone knows what might be happening that would be great.

And I thought OSC would be less taxing than mono...

Thanks
Brendan

[Mike in Rancho]

Hmm. Well if the same subs calibrate and stack into RGB in Siril, I presume the acquisition was okay.

Can't help with APP though as I don't have it, and Siril stacking baffles me.

In DSS, have you checked the settings for RAW/FITS DDP (Digital Development Process)? I also presume your subs are FITS?

In the FITS tab, make sure that the box for "monochrome FITS files are yada yada yada from a color camera" is checked off. You can then select a debayer pattern (probably RGGB).

Really that should do the trick, and DSS should flag it as a little tricolored icon as well as say "yes" to CFA. If not, then we'll have to dig deeper and maybe need some sample files.

ASTAP likewise has a box to check so you can tell it whether to treat a FITS file as mono or color.

[hixx]

Hi Brendan,
for APP You must define demosaicing in tab 0) in order to obtain color information from the RAW files
for a DSLR, under pattern, You can simply choose "supported" (which goes by camera model according LIBRAW library, else You need to specify which Bayer matrix is being used by Your camera (RGGB, GRBG, BGGR , GRBG or one of the more complex formats like RBGGGGBRGGGGRBGG). As algorithm I'd suggest Adaptive Airy Disk.
To confirm, You might want to watch the console output during normalization, it should state the color channel's results individually.

Clear Skies,
Jochen

[BrendanC]

Thanks all for your help.

I've had quite a tough time recently, trying to get the hang of mono and admitting defeat, then retreating to what I thought was an 'easy' option, OSC. I mean, you just point and click, and you get colour, right? Wrong!

Anyway, @hixx, it turns out that with APP I had to click the 'Force Bayer X-Trans/CFA' option to make it work. I don't know why, I would have thought it should really pick this up without having to force it, but all I know is, it works, so let's leave it at that.

In DSS, as @Mike in Rancho says, I had to click the 'Monochrome 16 bit FITS files are RAW files created by a DSLR or a color CCD camera', then I could select Generic RGGB. This, to my mind, is totally unintuitive, but what the hey, again, it works.

I was starting to doubt my sanity, I must admit, but I'm back up to speed now. Hopefully, having taken ten steps forward and 9.73493886 steps back over the past four months, I can start moving ahead again.

Thank you both again for your help.

Cheers,
Brendan

PS @Mike in Rancho, Siril absolutely baffled me too, but then I downloaded Sirilic which is really a front-end to protect you from its intricacies, and suddenly it made sense, so maybe give that a go. I'm only using it at a basic level, more out of interest than anything, but if you need any pointers just give me a shout and I'll try to help.

[hixx]

Hi Brendan,
it seems Your camera uses a Fuji X-trans sensor, hence the different pattern. As all patterns use different color to pixel association, picking the wrong pattern leaves the demosaicing algorithm with data that makes no sense, hence no color signal will be decoded. The best You can get in that case is a decent luminance signal.... in APP you will find question marks right next to the selection dropdown. If You hover over it with the cursor, APP will produce a pop-up where Mabula provides valuable information For more details, You would probably need to search the APP forum
Cheers,
Jochen

[BrendanC]

Thanks Jochen. Turns out I'd actually switched off the tool tips! So, switching them back on, tells me that I do need to activate the 'Force' tick box. It's the exact equivalent of the DSS check box mentioned above. So, I'm all good to go. Thanks again.