DSS vs Siril vs ASTAP

[Carles]

Hello all,

I'm trying out these three softwares for stacking my files to see if I get better results with one or the other.
For DSS and ASTAP I follow the recomended settings as per the Manual / website. And for Siril just guessed.

This is the ASTAP stack... is the only one of the three that shows this weird artifacts of blue and green pixels
around the image...

ARtifacts ASTAP.png (457.92 KiB) Viewed 9372 times

This one is Siril

Siril Stack.png (479.24 KiB) Viewed 9372 times

And this is DSS - which...to mee seems the more noisy one, and I don't understand why

DSS Stack.png (505.95 KiB) Viewed 9372 times

As a side note and curiousity... DSS and Siril, when open the file in AutoDev, has an strong
yellow cast before Wipe. And only ASTAP shows Clear blue / tale.

I Have not changed the white balance or anything in DSS, actually disabled any sort of white
balance as per the manual too. Any thoughts?

If anyone knows a good settings for Siril, would be great. So far just using sort of defaults. But
doesn't look bad...and it wasn't as slow as ASTAP.

FYI, the stack was in all of them with Sigma Clipping, 180 files of 300 seconds each.

Regards

Carles R.

[admin]

The ASTAP stack appears to show hot pixels that were succesfully dithered, but were - for some strange reason - not rejected during stacking. It is probably just a thresholding / stacking parameter configuration issue.

I cannot readily explain the DSS vs Siril difference though. That's quite odd.

[RICH-DSO]

I have compared DSS and ASTAP stacks in startools, and the ASTAP stack provides results that are much better than DSS. In DSS, i have tried all available options with the same results.
So. Like you I can't explain why ASTAP is more compatible with StarTools, but I no longer use DSS.
I am glad I discovered ASTAP.
A clean stack is key to generating, good colors, details and a good image.
R

[Carles]

The ASTAP stack appears to show hot pixels that were succesfully dithered, but were - for some strange reason - not rejected during stacking. It is probably just a thresholding / stacking parameter configuration issue.

I cannot readily explain the DSS vs Siril difference though. That's quite odd.

Right, that makes sense, Ivo! Was wondering what those blotches were, and was trying to look through the subs.. but I have 224! haha so gave up looking for those blue and green pixels.

And as for DSS vs Siril... I don't know, but for now Siril "wins" .. it makes the file cleaner. As said, I didn't change much of the settings so maybe there is something "StarTools unfriendly" kind of setting ON..but considering DSS gives me worse results... I don't know if I should try to change settings in DSS, maybe the way stack calibration frames ?? No idea.

I have compared DSS and ASTAP stacks in startools, and the ASTAP stack provides results that are much better than DSS. In DSS, i have tried all available options with the same results.
So. Like you I can't explain why ASTAP is more compatible with StarTools, but I no longer use DSS.
I am glad I discovered ASTAP.
A clean stack is key to generating, good colors, details and a good image.
R

Umm not really for me was the worse of all three. Although I also wonder about the "hue" when AutoDev the files.. ASTAP is the only blue, the other ones are yellow... wonder why :/


Carles

[RICH-DSO]

Carles, your question about stack wipe color ?

are you using a filter ? that may explain the color.

[Carles]

Carles, your question about stack wipe color ?

are you using a filter ? that may explain the color.

Hi Rich,

no, is not about the color. although is interesting that only ASTAP shows a blue hue , but the others yellow
I do use an Optolong L-pro filter with QHY8-L OSC camera.

But the post was more about the differences in the final staked file, comparing those 3 softwares

For Siril I use the included Script to stack OSC so I didn't make any adjustment. To me looks better. Just
wonder what other users experiences are with them

Carles.

[Carles]

So... here goes another test I did today.

Stacked my 9hours in 3min subs in Siril, with the old calibration frames and so on, just like DSS.
Result ? I don't really understand what Siril does, but I do like it..

Horse Head 9hours Done Siril Lines-1-2 50%.jpg (326.79 KiB) Viewed 9266 times

And here the comparision of both files, stretched the same in Nebulosity (just to bring up the gradients )
Siril stack Left ------ DSS stack right

DSS vs Siril Horsehead.jpeg (251.12 KiB) Viewed 9266 times

Ivo, if you read this, this is the "high speed " dataset I've sent you while back.

Regards

Carles.

[bobharmony]

Carles

I have just begun working with Siril as an alternative to DSS this past week, and am also liking what I am seeing so far. It seems that the stack produced by Siril shows a bit more detail than the DSS result. My particular interest is in Siril's capacity to apply background extraction from individual subs before stacking, as I image in a very light-polluted area and gradients are complex and fierce after stacking in DSS. Early results are promising but there is more testing to follow. I will be watching this thread with interest.

Bob

[Stefan B]

Hi everybody,

with my last image I had some problems with the stack generated by DSS. Because of the 80% moon it was difficult for me to seperate the outer parts of M106 from the noisy background. After seeing the processed DSS stack the first conclusion was that it's just stupid to image broadband during a bright moon. But with this thread in mind I had a try with ASTAP and got a much better result.

Not a masterpiece, but not a waste of time which has been my first impression with the DSS stack.

I don't have a nice comparison of the two stacks, but it appeared pretty obvious to me that ASTAP did a much better job not only in terms of noise but also in terms of signal in the galaxy. Afterwards I was wondering how many details were lost in my former images by using DSS. I had a try with a different data set (not broadband, but duo narrowband filter). The result was pretty disappointing although I applied the same settings. Probably I have to dig deeper in the settings.

A major drawback is the amount of time it takes for analysing and stacking the data. But in this case it saved the image and was worth it. Maybe I should also have a go at siril.

@RICH-DSO: You have worked with ASTAP on several data sets, right? Did you notice a difference in quality between RGB and SHO stacks? Are different settings required for broadband and narrowband? And also important for me: Do you know how to stack data from multiple nights? Couldn't find the solution for this. I think it's important that the lights from each night have to be calibrated with a distinct set of flats and dark flats. That doesn't seem to be possible in ASTAP. I came across the notion one can stack the data from every night seperately and afterwards stack the stacks. But then a night with two hours of data is weighed equally like a night with four hours of data. Not sure if that makes sense...

Regards
Stefan

[Cheman]

I have been using Siril lately and like the results. I've even had pretty good results stacking with Affinity Photo, which now has astropotography specific stacking. And you can often find it for half price of $25 on sale. It is a great alternative to photoshop.