Questions about Bad Pixel Map  

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(@minusman)
Red Giant Customer
Joined: 2 years ago
Posts: 97
September 24, 2018 18:43  

When creating a bad pixel map with my ASI294MC Pro something strange happens. The Amp glow is recognized as a hot pixel and if my Lightframe calibrated with it, disturbing pixels on the previously not see.

Screenshot (55)

🙃 

This topic was modified 4 months ago by minusman

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(@minusman)
Red Giant Customer
Joined: 2 years ago
Posts: 97
October 4, 2018 19:51  

Hello Mabula, should I do without the Bad Pixel Map in this case?


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(@vincent-mod)
Neutron Star Moderator
Joined: 2 years ago
Posts: 244
October 6, 2018 23:22  

Good question, I'm not sure if the BPM should include things like amp-glow actually, @mabula-admin knows all about that. But as a general rule, if the calibration frame causes a problem in the end-result, it's better to leave it out.

This post was modified 3 months ago by Vincent Groenewold - Moderator

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(@minusman)
Red Giant Customer
Joined: 2 years ago
Posts: 97
October 14, 2018 13:13  

Hello Mabula, did you have a look at Bad Pixel Map?


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(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 1844
October 14, 2018 17:02  

Hi @minusman,

I have tested this on data that I have of a ZWO asi183mm which has very strong amp-glow.

I am seeing the problem that you have as well, allthough not so prominent, shown first is MasterDark, then BPM:

MasterDark stretched
BadPixelMap from MasterDark

This was with APP 1.068 and a hot pixel kappa of 2.0.

I get the following calibration result (data provided by Yves van den Broek @yves_van_den_broek ) , first is shown an uncalibrated frame, then calirbated with a MasterBias, MasterDark and the Bad Pixel Map and with the Adaptive Data Pedestal on. The Adaptive Data Pedestal is needed here.

NGC688 Soap 300sec 1x1 Ha Light uncalibrated
NGC688 Soap 300sec 1x1 Ha Light calibrated

So this is fine I think.

Is the BPM in your case messing up data calibration of the light frames?

Can you show an example/screenshot ?

The issue most likely has to do with some changes that I made in the Bad Pixel Map creation. I should be able to adjust here. So I will have a look and test if I can improve this.

Mabula

 

Main developer of Astro Pixel Processor and owner of Aries Productions


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(@minusman)
Red Giant Customer
Joined: 2 years ago
Posts: 97
October 14, 2018 20:24  

Hello Mabula, I once processed another record of dark frames with cooling turned off. Since the problem hardly occurs.
I will again make new Darks and flat frames for security.
When creating BPM, do I need a Master Bias or Master Dark Flat? If I omit it comes a warning.


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