Quote:
Originally Posted by Mighty_oz
Is this the theory now, no bias if u take darks or just for these newer cameras as i have an older ccd 
Thanks |
While I've covered this elsewhere on ISS, if you take a non-trivial duration
dark frame...and by that I mean one where dark current is a factor, say longer than 1/10th of a second, then you don't need a bias frame.
Just so we are clear: a bias frame = zero second dark frame
So any dark frame longer than zero seconds (i.e. any dark) already has a bias pattern.
When you subtract a dark frame, you also subtract *any* bias.
To attempt to also take a bias frame and further subtract it after dark frame subtraction *increases* the noise.
In short, don't do it.
Hope that helps