Sky Background

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Morten Lerager
Posts: 15
Joined: 08 Oct 2021, 14:53
Location: Denmark

Sky Background

Post by Morten Lerager » 14 Nov 2021, 20:09

Hi'
After a preprocessing with 20 frames of Pacman I get a Report
I get a table where I can see the sky getting darker as time goes by :

But how is this, to be read. What is the Y axe with a value of 2190 ?
Can I translate it into a Bortle value https://en.wikipedia.org/wiki/Bortle_scale
HEQ5 Pro 150PDS 60mm Guide Lacerta
Baader MPCC EOS 2000D. AA8

merlin66
Posts: 22
Joined: 08 Jan 2019, 05:38

Re: Sky Background

Post by merlin66 » 14 Nov 2021, 23:21

Morten,
I'd assume that the minor (0.45%) improvement is due to the improved SNR with the stack.

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Morten Lerager
Posts: 15
Joined: 08 Oct 2021, 14:53
Location: Denmark

Re: Sky Background

Post by Morten Lerager » 15 Nov 2021, 08:54

Thank's

If I only gain 0.45% SNR then I didn't hat to stack them at all.
And if I fiddle with the filenames it will come out with another table as you see.
It's seems AA has it's one filename sorting. Expecting a numeric value in the file name.
So I still want to know, what is the graph's Y axe ?
And can I translate it, into a Bortle value ?
HEQ5 Pro 150PDS 60mm Guide Lacerta
Baader MPCC EOS 2000D. AA8

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Rudi
Posts: 113
Joined: 08 Jan 2019, 04:47

Re: Sky Background

Post by Rudi » 15 Nov 2021, 13:08

"sky background" is the average ADU value of the background in the image.
/Rudi

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Morten Lerager
Posts: 15
Joined: 08 Oct 2021, 14:53
Location: Denmark

Re: Sky Background

Post by Morten Lerager » 15 Nov 2021, 15:22

Ahh, thank you Rudi.
Then it would not be possible to convert to Bortle I give.
Bortle is for the eye, ADU for the camera, Gain etc.
But the picture background are dark, and ADU 2100 is pretty dark :mrgreen:
The curve shows me the sky getting darker as times goes by.
Right until someone hits the light inside or outside the house.
(don't hope it was the wife :oops: )
HEQ5 Pro 150PDS 60mm Guide Lacerta
Baader MPCC EOS 2000D. AA8

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