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Old 20-02-2013, 12:51 PM
acotiga (Andrei)
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Star white balance calibration

In short, what stars do you use for white balance calibration? Alpha Centauri or any other G2V class star? If not A Centauri, what else? May I also ask for a hint about the average exposure duration so the star doesn't get above 1/3 ADU?

Cheers.
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Old 20-02-2013, 08:40 PM
binofied
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I used to just do it by eye. I am just starting to play with eXcalibrator. Haven't had any experience with it yet and there seems like it has a few steps so learning curve may be a bit steep.
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Old 20-02-2013, 09:20 PM
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I've used G2V stars from this list in the past:
http://www.gemini.edu/sciops/instrum...dards/G2V.html

These days I mostly use eXcalibrator. It is a little complex to use the first couple of times but it's not big deal if you follow the doc and only use 16-bit integer FITS files.

Cheers,
Rick.
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Old 21-02-2013, 06:15 AM
acotiga (Andrei)
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That's one of those WOW moments in life. I had no idea this nifty little program existed. It's excellent. Cheers you guys.
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Old 21-02-2013, 02:09 PM
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Quote:
Originally Posted by RickS View Post
I've used G2V stars from this list in the past:
http://www.gemini.edu/sciops/instrum...dards/G2V.html

These days I mostly use eXcalibrator. It is a little complex to use the first couple of times but it's not big deal if you follow the doc and only use 16-bit integer FITS files.

Cheers,
Rick.
EXcalibrator is pretty good. I used it all the time until I switched to PixInsight, which has good methods for white balance.
Geoff
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Old 21-02-2013, 02:32 PM
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Originally Posted by ghsmith45 View Post
EXcalibrator is pretty good. I used it all the time until I switched to PixInsight, which has good methods for white balance.
Geoff
I use PI too so I often try both eXcalibrator and PI ColorCalibration and then decide which I like the best
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Old 21-02-2013, 05:45 PM
acotiga (Andrei)
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You guys brought this onto myself so you have to help me now

Aladin doesn't want to add the stars from the catalog. It gives an error something about CSV calibration. Do you have any ideas? It only happens with some but not all.
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Old 21-02-2013, 06:55 PM
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You guys brought this onto myself so you have to help me now

Aladin doesn't want to add the stars from the catalog. It gives an error something about CSV calibration. Do you have any ideas? It only happens with some but not all.
It's not an error message I can remember seeing before. When does it happen? When you are trying to load a catalog or later in the process?

Cheers,
Rick.
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Old 21-02-2013, 07:02 PM
acotiga (Andrei)
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It's happening while trying to load the stars from the catalog.
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Old 21-02-2013, 07:17 PM
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Here's what I do to load the catalog:
  • Drop the WCS (plate solved) file on Aladin. It will display the image.
  • Click on the menu: File> Load catalog> Surveys in VizieR> NOMAD1
  • Wait while Aladin downloads data from the Internet (green "LED" flashes) and eventually a selection of stars will be highlighted
  • Now you're ready to load the local filter...
I tend to use Aladin 7.5 in preference to Aladin 6.005. I found Aladin 6 was slower and sometimes timed out. Aladin 7.5 displays an additional "Server selector" dialog which allows you to select a smaller or larger Radius. Smaller is faster. You can probably do this somehow in Aladin 6 too if you you know what you're doing.

Give that a go and see if you get a bit further.

Cheers,
Rick.
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  #11  
Old 21-02-2013, 07:28 PM
acotiga (Andrei)
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Cheers. That's what I did...will see. I'll download and install 7.5 and give it a go as well.
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