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Stacking test

Posted: Thu Feb 18, 2016 5:40 pm
by Heno
Hi everybody. My first post at the forum.
I'm trying to get off on the right foot from the start so I've done a hand full of stacking examples with various settings using DSS and ImagesPlus. I now wonder if there is some way I can see if any of these files are linear? The input files were all Nikon RAW btw.
If that is a job for experts I would really like one of those experts to have a look at the files included in the link below and tell me which one(s) are linear, if any. Or which one would be the best starting point for development in Startools.

Thanks in advance,
Helge

https://www.dropbox.com/sh/epozze0yiiq4 ... wB0da?dl=0

Re: Stacking test

Posted: Sat Feb 27, 2016 10:58 pm
by admin
Hi Helge,

It's somewhat hard to tell without knowing integration times, target and equipment used.

In general, linear data will show very few stars (only the brightest will show), while noise grain should not be visible. Non-color balanced data from OSCs or DSLRs tends to show a green, blue or teal bias...

Re: Stacking test

Posted: Thu Mar 03, 2016 7:04 pm
by Heno
admin wrote:Hi Helge,

It's somewhat hard to tell without knowing integration times, target and equipment used.

In general, linear data will show very few stars (only the brightest will show), while noise grain should not be visible. Non-color balanced data from OSCs or DSLRs tends to show a green, blue or teal bias...
Hi Ivo.
I thought this might not be so easy to find out. I've made a few development attempts and for now I'll use the DSS as one of these seem to (initially) give the best result. (The posted examples did not actually have a target. I missed out on it :oops: )

Thanks for trying,
Helge

Re: Stacking test

Posted: Sat Mar 05, 2016 3:33 am
by admin
If you feed DSS the RAW files, and use the settings as shown here;
Image
and use autosave.tiff or autosave.fts, then you should be good...

Hope this at all helps!

Re: Stacking test

Posted: Sun Mar 06, 2016 7:10 pm
by Heno
Thanks Ivo, I'm shure it will.

I see that you recommend "Median". I will try that as well.
DSS have different ways to handle RAW and TIFF files as shown in below file. Which would be best to use to keep virgin data?

Also I have problems opening the Autosave.tif files that DSS is autaomatically generating. I don't see why, but I'm told is is an incorrect format. So I have saved the stacked result to a different name. But there are three saving options and they seem to give significantly different results, at least at first glanse. Any recommendations?

Helge.
Dss_settings.png
Dss_settings.png (74.45 KiB) Viewed 9112 times

Re: Stacking test

Posted: Mon Mar 07, 2016 7:28 am
by Heno
Hi again Ivo.
Sorry for all these questions. I did a read through of all the technical stuff on DSS home page last night and I think I understood most of it. The part I could not find anything about was the different file saving options. But I'll have another go at that. It got really late so I may have missed it. :sleeping-sleep: ;)
DSS gives a number of recommendations based on the files included in the stacking process, but those may not be the best for keeping linear data. So I'm trying to understand what each option does and how it affects the various steps in the stacking process. And I will, with time!

Helge

Re: Stacking test

Posted: Mon Mar 07, 2016 7:15 pm
by LanFeusT
Hey Heno, you can just save to a FITS 16bit file, that's what I save to and it works fine with ST!

I believe you can also change the settings so that the Autosave file is done using the FITS 16bit so you don't have to manually save.

The other options all seem fine as well!

Re: Stacking test

Posted: Tue Mar 08, 2016 5:30 pm
by Heno
LanFeusT wrote:Hey Heno, you can just save to a FITS 16bit file, that's what I save to and it works fine with ST!

I believe you can also change the settings so that the Autosave file is done using the FITS 16bit so you don't have to manually save.

The other options all seem fine as well!
Thanks LanFeusT,
I will do that in the future. Just started scratching ST so I am uncertain about everything. I would like to have at least the starting point correct and then work my way from there. :)

Helge

Re: Stacking test

Posted: Wed Mar 09, 2016 6:35 pm
by Burly
save file as =save as fits