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Trifid Nebula
Posted: Tue Jul 20, 2021 9:41 am
by tango13
Hi all,
after some time I finally managed to get some photons home
Processed with the latest stable version (1.7.461 Maintenance Release 6).
Pretty happy with the outcome.
Thank you.
Piero
Click here for details
Trifid Nebula
by
tango13 on
Telescopius
Re: Trifid Nebula
Posted: Tue Jul 20, 2021 10:03 pm
by ionia23
Okay, this is truly glorious. I do have one question about the image capture data.
I noticed you reported 67 light frames at 180 seconds each are in the stack. Isn't that total overkill? I've got mixed answers about image stacking. I've been told 20 good frames is a pretty good "go-to" amount. Any improvement beyond that is very minor and requires going to 50, then 100 frames respectively. What do you think?
Re: Trifid Nebula
Posted: Wed Jul 21, 2021 7:00 am
by tango13
Hi,
this is probably THE question among astrophotographers
It depends very much on the conditions you are shooting in, i.e. the brightness of your object, light pollution, frame exposure and many others.
The math behind it all says that the amount of noise reduction you get from stacking is the square root of the number of individual sub frames stacked, so yes, the more frames you stack the more the curve flattens.
That means that each sub you add contributes a little less than the previous one, but it gives its contribution anyway.
So from my (limited) experience and knowledge, I've come to the simple conclusion that the more frames I can get on a given object, the better
Normally I shoot a single object per night, concentrating my little time to collect as many photons as possible on that object.
I suggest you read the following:
https://jonrista.com/the-astrophotograp ... asics/snr/, it's one of the most thorough analysis I've ever read on the subject.
Thank you.
Re: Trifid Nebula
Posted: Thu Jul 22, 2021 3:27 am
by admin
@tango13 sums it up nicely!
A video on the subject that I have found absolutely amazing is this one by Craig Stark (author of Nebulosity and PHD);
https://www.youtube.com/watch?v=EO4QFb3ydNM
If you ever watch one video on astrophotography, let it be this one!
Re: Trifid Nebula
Posted: Thu Jul 22, 2021 8:00 am
by tango13
Fantastic video!
Thank you for pointing that out, Ivo.
Re: Trifid Nebula
Posted: Fri Jul 23, 2021 6:26 am
by Stefan B
Great video! But now I want a faster scope, a more sensitive sensor and darker skies ... but
Awesome Trifid by the way,
@tango13 !
Re: Trifid Nebula
Posted: Fri Jul 23, 2021 7:03 am
by tango13
Thank you Stefan!