Which stacker?

[szymon]

So I am looking for a new stacking program. I get along well with DSS when it works and ASTAP, but I want something g more refined. My current plan is to get a trial of AstroPixelProcessor, on the advice of a friend. Any others I really should try? What do people recommend?

[admin]

Just wondering; what do you mean by "more refined"?
What are some features you are after?

[szymon]

Just wondering; what do you mean by "more refined"?
What are some features you are after?

DSS only ever really works for me with median for everything. Even then, one bad frame can ruin a stack, and it really isn’t helpful with deselecting frames or looking through them to find bad ones. It seems to have issues with complex file lists (from multiple nights) and saving them. It’s behaviour is inconsistent; sometimes if things are going wrong, I restart it and it behaves differently.

ASTAP stacks very well, and has many options for how to align frames. It’s process of matching calibration frames is great, and it’s developer is very quick to add new functionality. However it cannot easily handle data from multiple days (I end up stacking stacks), and it is “clunky” to use for want of a better term.

I spend too much of my life trying to get good stacks from my data. I discuss it on forums or chats and then someone takes a look at my data and stacks it in something else...and it comes up as a beautiful clean stack. So I am clearly missing something! I want something easy to use and intuitive but that just works

So again — what do you guys use to create your stacked data for StarTools to process?

[admin]

Hopefully other people will chime in, but here are a few "premium" (paid) suggestions in order of expense;

• I hear good things about Astro Pixel Processor. I have somewhat limited experience with the datasets (or any trademark "quirks") its produces however, as it hasn't been around that long yet and is still under development (it takes a while to get these things right).
• Though I have my issues with PI's post-processing engine, I (and many other StarTools users) hold its stacking and pre-processing capabilities in very high regard. For example, for the longest time, it was the only application (that I know of) that would dispense with white balancing and matrix-correcting DSLR datasets bty default - presumably recognising the potentially harmful effects on cross-channel noise propagation. It's mature and produces excellent results all round.
• A number of "high-end" StarTools users also swear by MaximDL for stacking.

The above suggestions are mostly based on the selection of datasets I've been seeing lately from the StarTools userbase. I cannot attest to their UI or "clunkiness".

There are a lot of subtleties to pre-processing and stacking, with many edge cases to cater for and many variables to take into account. How well a stacker performs can be highly dependent on your gear and optical train. What you've been doing makes a lot of sense; try them all!

[szymon]

Indeed, APP is first on my list to try out I think. I'm avoiding PI because the price is too high for me at this time (I think it's unfair for me to do a 'trial' of something that I am sure I won't buy); I'm saving up for a camera with set point cooling, which has to be my first priority, but maybe I'll look at it in the future. Maxim I'd not heard of particularly for stacking, but will take a look -- thanks!

[admin]

Ok, great! Any compatibility issues, things that might impact Tracking, or any other quirks you come across during the trial(s) - let me know.

[prusling]

I've adopted Siril over the past few months via the excellent front-end utility Sirilic which simplifies the setting up for pre-processing, alignment and stacking and passes the necessary commands to Siril to do the work.

The main advantages are as follows:
- it's free (though I'm sure donations are welcome)
- it can cope well with DSLR, OSC, LRGB, narrowband and multiple sessions, and where appropriate will align the individual filter stacks with each other
- it uses winsorized sigma clipping which some say is better than regular; I've found that as few as 5 images are needed to bring this into play which is a big advantage when taking long exposures (e.g. narrowband) and dithering
- it uses all memory and CPU cores available; I found that DSS would take an absolute age processing the many large image files from my QHY183 OSC arising when using shorter exposures; Siril was lightning fast in comparison!
- the results look very good to my eyes, and seem to provide a sound basis for StarTools processing

The main disadvantage is that it creates many intermediate files which requires plenty of free disk space.

I could provide a basic tutorial on how to use Siril via Sirilic if that would be useful?

P.S. Thanks to Luke Newbould for pointing me in that direction.

[szymon]

I had heard of Siril but when I tried it out I couldn’t get it working; from what I remember most of the help at the time was in French and I couldn’t work it out! A tutorial would be most welcome

[admin]

I'd also be interested in learning more about how you use Siril!

[AndyBooth]

Yes, please post a tutorial for Siril,
That would be very kind indeed.