ASTAP vs DSS

[Starwiz]

Having been a user of DSS for several years, I've recently had a look at the stacking feature in ASTAP.

The two images were both stacked using the same lights, darks, flats and dark flats.   

Ha = 17 x 360s, Temp -10 deg C, Gain 200, Offset 50.

30 x matching darks.

30 x flats

30 x dark flats.

The images were stretched to about the same level in Gimp.

I then zoomed to 250% and cropped, to show the comparison better.

To me, the ASTAP stacked image looks a lot cleaner and a bit sharper too.

Has anyone carried out a more extensive comparison between the two stacking programs?

Edited March 14, 2021 by Starwiz

[The Lazy Astronomer]

Hmm, interesting. I think I do remember seeing a thread on here a little while ago comparing DSS to APP and PI, the conclusion was that DSS was the worst of the three, but then APP and PI are somewhat expensive software, so considering DSS is free, it's a pretty good option. 

However, being that ASTAP is also free, this may change things. Will definitely be trying it out for myself now. 

[Seelive]

I assume an identical stacking method was used in both programs? Is the apparent difference significant for all equivalent stacking methods?

Edited March 14, 2021 by Seelive
'the same' changed to ' an identical'

[Paul M]

I use both and I'm a big fan of ASTAP for its various features.

I do find that it can do weird things, particularly with my usually poor subs. I gives me double stars sometimes and I can't always identify why. 

ASTAP can process the stack too and can give usable images but mostly by way of presets. I often use it to see if a stack is worth any further effort but ocassionally it beats my processing efforts in PS! But that isn't difficult.

[rnobleeddy]

I've never used ASTAP (but will give it a go!) but as others stated, DSS alone has a lot of options, so you'd need to make sure you're comparing apples with apples.

[Starwiz]

On 14/03/2021 at 15:35, Seelive said:

I assume an identical stacking method was used in both programs? Is the apparent difference significant for all equivalent stacking methods?

Yes, I used the 'Average' method and used stars for alignment in both programs, although ASTAP has other alternatives.

[rickwayne]

I spent the money for APP, but I'm pretty impressed with ASTAP. Lots of little things to like, e.g. the "blink" feature.

[happy-kat]

I prefer the DSS image the other looks too heavy and lacking detail/depth

[The Lazy Astronomer]

Played around with it a bit yesterday, there wasn't a whole lot in it really. In areas of low signal (i.e. background sky), the stack appeared less noisy, but in areas of higher signal I couldn't discern any difference between them. Further experimentation required, methinks!

[Clarkey]

It's an interesting subject. I normally use APP but I have used DSS. I did see a review a few weeks ago that compared 4 different stacking options which came to the conclusion that APP was the best option. However, it is at the expense of being much slower than some of the others. The other important consideration is likely to be the type of target. Nebula, galaxies, star clusters etc. will undoubtedly need different processing to get the best out of them. As will OSC and mono. On top of this, a lot of the results in AP are very subjective make the differences even more difficult to judge.

Ultimately I think multiple image types would need to be processed from start to finish in different software to give a final definitive answer.

By definitive, I mean an answer that everybody will have a different opinion on😂

[Starwiz]

20 hours ago, happy-kat said:

I prefer the DSS image the other looks too heavy and lacking detail/depth

It doesn't look that way on my screen.  Differences in displays & settings, perhaps.