Stacking multiple live stacks in DSS

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mAnKiNd
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Stacking multiple live stacks in DSS

Post by mAnKiNd » Mon Jun 12, 2017 7:51 am

Hi there, just a question of correct methodology really.

Say i capture a live stack of a target the first night of say 1000 frames. Then i do the same the second night and get 700 frames, third night 1500 frames etc... If i choose to save individual frames, then obviously i can load them all up in DSS and do a stack that way, but that means id have folders with HUGE sizes in my hard drive.

Therefore, say I wanted to stack the 3 final saved images in DSS. Would each individual stack need to have the same amount of frames in it i.e. all of them should be 1000 frames, for the SNR of each stack to be the same, or does it not really matter if the stacks from different nights contain a different number in them. I ask this because i might not be able to achieve the same number of frames in a live stack in during different nights. I'm also not 100% understanding the stacking process in DSS to know if this would be an issue or not.

Thanks for the help.
Minos

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Re: Stacking multiple live stacks in DSS

Post by admin » Mon Jun 12, 2017 6:25 pm

Hi Minos,

I think the answer is that it will sort of work. If your stacks on different days/times were all the same length (total exposure) then everything would be fine. If they are different lengths then DSS won't know that so will assign equal weights to each, rather than assigning more weight to the 1500 frame stack than the 700 frame stack.

The way it works now, I would say that the best approach would be to save the stacks as 16 bit stacks and then stack in DSS and accept that they all get the same weight.

I *think* that if I fix the saving to include the total exposure time then the right approach would change to saving a 32 bit stack and letting DSS take care of the exposure variations, but that will be for a future version.

cheers,

Robin

mAnKiNd
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Re: Stacking multiple live stacks in DSS

Post by mAnKiNd » Thu Jul 06, 2017 11:24 am

Sounds like a good plan!

Cheers Robin
Minos

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Re: Stacking multiple live stacks in DSS

Post by Pkay » Sun Oct 22, 2017 3:59 am

Any progress for Live Stacking?
I think it would be very useful to be able to automate the saving process ie: after 10 frames stacked, or 2 minutes etc.
I understand that at the moment I have to do the saving manually?

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Re: Stacking multiple live stacks in DSS

Post by admin » Sun Oct 22, 2017 7:11 am

In the latest 3.1 beta build it should be possible to script the capture of multiple stacks - see viewtopic.php?f=19&t=393.

It looks like the exposure time is saved into the saved fits file, but in milliseconds, not seconds. I will fix that in the next beta update.

cheers,

Robin

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Re: Stacking multiple live stacks in DSS

Post by mAnKiNd » Fri Dec 08, 2017 10:28 am

Hi Robin, I just saw this now, thanks I'll give it a try and feedback here.

Many thanks
Minos

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