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Dark Bias and Flats

astrophotography ccd Celestron CMOS dso imaging SCT
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#1 arshadwm

arshadwm

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Posted 24 January 2021 - 04:15 PM

Hi all. I need advise. 
 

while taking dark and bias, can I block the corrector plate with black plastic cover like bathinov mask but without any cuts fully covered. And same for flats if I cover with white plastic cover ? 

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#2 Alex McConahay

Alex McConahay

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Posted 24 January 2021 - 04:36 PM

Darks and biases should have NO light hitting the sensor. Cover the end of the tube with an opaque cover. 

 

In addition, if your have any light leaks, an open tube, or anything else such as that, you should cover them. 

 

As I said....no light at all during darks and biases. 

 

Flats are fine with the translucent cover. 

 

 

Alex


Edited by Alex McConahay, 24 January 2021 - 04:37 PM.


#3 sg6

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Posted 24 January 2021 - 04:49 PM

Darks and Bias are in effect both black = no light getting to the sensor at all.

It is the duration of the 2 that differes but in simple terms both are lightless.

 

Flats are with some form of diffuser over the scope+camera system and that has to be evenly illuminated. Many will suggest a white T-shirt or similar material BUT do not illuminate with a single light source directly in front as the center will be brighter. I place 2 light sources to either side but out of the view of the scope. Seems to work OK, and fortunately I have 4 LED lamps I can use.

 

The Flats take a bit more effort and setup then the Darks and Bias.




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