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Flat frames rarely work in Nebulosity

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28 replies to this topic

#26 StevenBellavia

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Posted 12 February 2018 - 03:31 PM

I would start with 50%. They go fast. Stack and test.

Yes, I am getting ahead of myself here.  If I did indeed have 1/8 histogram all this time, using the AV mode within APT, then I wasn't even close.

 

1/2 should do the trick.  But you only get one chance for your flat frames.  I'd rather do them all in the field then find out they are no good, after processing.



#27 AbPho

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Posted 12 February 2018 - 03:48 PM

Why one chance for flats?

#28 Michael Covington

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Posted 12 February 2018 - 08:40 PM

Why one chance for flats?

What he means is that they are intended to record all imperfections in the optics, including dust on the sensor.  If you try to take flats on another occasion, any dust that might be on the sensor will have moved -- and the focus will probably be a bit different, and the position of the camera.


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#29 AbPho

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Posted 12 February 2018 - 09:00 PM

Gotcha.

With a dSLR and dedicated camera lens I am not too worried about that then. The orientation is the same and no new dust is introduces because the lens never came off. But with a scope things could be a little different.
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