Hypathetic Question regarding data.

[Perkil8r]

Is there any reason why a sub could not be used multiple times in a stack?

People say you need lots of data, and sub length doesn't matter as much as the amount of them. With that in mind, surely 2 subs of equal ISO and Exp are going to be near as damn it identical aren't they? Or does each sub capture a slight variation due to atmospheric variations? Just curious as there must be a reason why we don't just copy the same sub 100's if not 1,000's of times to stack them.

[+RonC]

Mike ,I think you answered your own question! I'm only a beginner but have read a lot!

[Doc]

Yep Ron is right, they have to be slightly different or you are just copying the same data.

[Guest Kheldar]

Simple answer, to increase the signal to noise ratio.

In fact, here's some theory : http://deepskystacker.free.fr/english/theory.htm

[Perkil8r]

Thanks Stephen, that explains a lot. (if I understand it all is another matter lol) So I was right in a round about way.

[Rusty Strings]

Excellent question, I've wondered the same thing myself.

[andyboy1970]

If you look at a planetary Avi you can see how much atmospherics effect the image but with lots of data you can cut the rubbish out and produce better images.

The other thing when looking at Avis you notice every so often new bits you haven't seen flash up.

[Perkil8r]

Light and photons etc are curious little devils. You'd imagine that you can "see" everything that's there all the time, but I did read somewhere that the eye only gets so many because it takes so many to register, or something like that. So I suppose it does make sense that the more pictures you have the more likely the chances of capturing the crafty little devils. I guess we could look at it like fishing for photons, stick your net in the lake and you'll maybe catch one or two, keep sweeping the lake and eventually you'll get them all, a couple at a time.