DSS vs Siril vs ASTAP

[Carles]

awesome thank you!!

Once tried to modify a Scrip to eliminate Bias, since a friend of mine using an asi294mc doesn't need it, and wanted to try Siril
I think it kinda worked, but was very tedious... deleting all bias related from the text, plus the text editor shows the text all together!
how do you open the file to see it all text more... organized?

thanks for your help and tips

Carles.

[Troy Galebach]

Carles,

I am probably the least knowledgeable person responding to your question about Siril.
I have used Siril since I began this hobby several years ago. I to get a yellowish cast when I take a stack from Siril and begin to process it in ST.
There are many factors which will cause this with light pollution being a big one, and of course the Moon. I also use Siril to break .SER files into .fits images to stack and bring into ST. That said, I haven't found this to be a large problem because when I process, I lose most of that cast, and what ever still exists in my final image, I use RawTherapee to adjust the black point. I don't think purists would be happy with that solution, but it works for me and the OSCs I use for imaging. Since Siril is actively being developed, I think it is a great choice. I have PixInsight on my machines, but find it too onerous to use.
Since I don't run Windows or Mac, I am limited to packages which run on LInux.

I'm working on an image of the Rosette Nebula, and have the yellow cast, and if I can figure out how to share the final image with you I will do so. Don't expect too much, I think I took 20 frames at 1 minute exposures. The reason I said that is that I suspect that I often capture with too much gain. The higher the gain, the more of the yellow I see, using less gain less yellow. That may just be me though. Cameras, and Scopes can make a difference too. I have and FSQ-106 and there is a noticeable difference between it and my ES-127. The same can be said for each of the 2 cameras I use.
Regards,
Troy

[Cheman]

Carles
On my windows 10 machine I just right click, select open, and it opens in notepad

[Carles]

Carles,

I am probably the least knowledgeable person responding to your question about Siril.
I have used Siril since I began this hobby several years ago. I to get a yellowish cast when I take a stack from Siril and begin to process it in ST.
There are many factors which will cause this with light pollution being a big one, and of course the Moon. I also use Siril to break .SER files into .fits images to stack and bring into ST. That said, I haven't found this to be a large problem because when I process, I lose most of that cast, and what ever still exists in my final image, I use RawTherapee to adjust the black point. I don't think purists would be happy with that solution, but it works for me and the OSCs I use for imaging. Since Siril is actively being developed, I think it is a great choice. I have PixInsight on my machines, but find it too onerous to use.
Since I don't run Windows or Mac, I am limited to packages which run on LInux.

I'm working on an image of the Rosette Nebula, and have the yellow cast, and if I can figure out how to share the final image with you I will do so. Don't expect too much, I think I took 20 frames at 1 minute exposures. The reason I said that is that I suspect that I often capture with too much gain. The higher the gain, the more of the yellow I see, using less gain less yellow. That may just be me though. Cameras, and Scopes can make a difference too. I have and FSQ-106 and there is a noticeable difference between it and my ES-127. The same can be said for each of the 2 cameras I use.
Regards,
Troy

Hi Troy,

thank you for your insights about Siril

I'm happy with Siril for stacking, and usually don't run into problems. Yellow cast is totally normal as I use an OSC with L-pro filter and tends to give that cast untill I use whipe or in siril Background extraction. then colours are pretty normal.

What cameras are you using? is weird you get more yellow cast as higher gain... I use a qhy8L and got 0gain, but it is a CCD, not CMOS. so no idea...

you have really good optics! never had either of them, but their fame speaks for itself hehe specially the Takahashi

Hope you can share that rosette of yours,
Thank you!

Carles.

[Carles]

Carles
On my windows 10 machine I just right click, select open, and it opens in notepad

oh...well, I use windows 7 for now, and it just open in a notepad but all the text together without spaces...so a bit messy.

[Cheman]

try a different editor... one that doesnt loose formatting? word..or maybe wordpad. See what you have on your computer

[Carles]

Hi Che,
you're right, I've tried opening it with Office Word and it kept the format
thank you!

Carles.

[Cheman]

awesome

[KlausKlaus]

I did my own comparison. Here‘s what I came up with: https://www.cloudynights.com/topic/8143 ... tatistics/

[Mike in Rancho]

I did my own comparison. Here‘s what I came up with: https://www.cloudynights.com/topic/8143 ... tatistics/

Klaus that is quite cool! Nicely done.

I wonder what we can take from that though in regards to increase of statistical SNR? And if the test will hold up across more than one sample image and differing types of targets/fields.

I get the sense that each stacker sort of has its own way of going about things, and some stuff you can't change, while others may let you. For example DSS allows you to turn off normalizaton for sigma rejection (the ST guideline), but I think in ASTAP it might be built in. However, ASTAP does give you a number of choices for OSC file translation, whereas in DSS it is fixed. Bayer interpolation can often differ, as can frame alignment and alignment interpolation too.

No statistical analysis, but a couple months ago I anecdotally compared different bayer algorithms for my OSC-SHO Rosette. For me, as well as some others who checked it out on CN, the ASTAP detail seemed cleanest. I have also noticed that some of the funky color gradients I am getting with my Newt (still working on that) seem easier to deal with out of ASTAP.

Each of these was processed to completion in ST as reasonably matching as possible (ST being dynamic and all).

Top left is DSS bilinear. Top right is DSS superpixel. Bottom left is DSS Bayer drizzle (bicolor only, I didn't have my SII filter here). And bottom right is ASTAP but with the AstroSimple interpolation rather than bilinear. Looking at the explanation of Han's algorithm on the website it seems to make sense. Other than that I use the ST guidelines of no color alterations.

Rose quad CFA comparo.jpg (491.73 KiB) Viewed 4832 times