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Dim question about creating a bpm!


(@anniemorello)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
Topic starter  

I suspect this question reflects a lack of understanding about bpm's! I have no problem with the processes of creating a bpm, creating master files or a fully integrated stack of data.  When I create a bpm am just loading flats without any bias frame calibration and darks of course - is that right?

 

Pam


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4736
 

Hi Pam,

So you load in your flats, darks and bias for the bpm creation. For the darks it's best to take your longest exposures.


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(@anniemorello)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
Topic starter  

Ok - got it.

Thanks for such a speedy response Vincent!

Pam


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4736
 

You're welcome. I am going abroad again though so this might be my last week of speedy responses. Hope I'm online asap after that though.


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(@anniemorello)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
Topic starter  

No worries Vincent.  However!   I remain confused about some aspects of creating a bpm.  Sarah Wager, in her tutorial simply loads flats and darks using hot pixel kappa of 2 and cold pixels 50% albeit in an older version of APP than I am using.  When I do the same I get a calibration warning that 'to be able to perform accurate flat field calibration the provided flats need to be calibrated by (in my case) a masterbias of the same ISO/gain value as the flat frame.' If I create a master bias and load that together with flats and darks I don't get that message - is that right?

I notice that Sara Wager when looking at the details of her bpm  suggests that the bad pixel percentage and hot pixel percentage should be around 3% whereas mine is 2.483% - is that ok or is something amiss?

Pam


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4736
 

Hi Pam,

Yes that's fine, I'm note sure but it might be that Sara already calibrated her flats... or it's a change from past versions. Anyway I include them and the masters are created including the BPM. Those percentages are fine, you can try to use the BPM instead of a masterdark in previous data to see if it's effective.


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(@anniemorello)
Brown Dwarf Customer
Joined: 3 years ago
Posts: 13
Topic starter  

Thanks again Vincent - I will check out by using a bpm instead of a masterdark on earlier data.

 

Pam


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