|
My calibration routine is
50 darks per exposure time I plan to use to generate master flats (Time consuming but I only do it once or twice a year)
100 bias as they don't take long to shoot and I re use the resulting master bias for months.
25 flats per filter per session. I shoot dawn sky flats and it happens so it is no bother to me. But with dawn flats you really need a good number so that dithering between shots allows for any visible stars in each flat to be rejected.
The flats I calibrate with the master bias to generate a master flat per filter per session that I can store with the appropriate lights.
The lights I calibrate with a bad pixel map, the master flats and either the master bias or the correct length dark. With the ASI294 bias frames were no good and it has a predictable glow so darks were essential but the ASI2600 (Both MC and MM) have essentially zero glow and good bias frames so I am using the master bias more and more now and darks less and less.
I shoot lots of bias and dark frames as it is a relatively small time investment in smooth masters that I can re use for months and months.[/QUOTE]
I take dusk flats with a white even cloth over the end of the scope. You have to be fast and efficient as light fades quicker than you think.
With 7 filters to flat and some 2x2 as well as 1x1 its quite a few. But I get it done with no real trouble unless I start too late.
Or when I had an Apogee U16M it took 35 minutes to cooldown so if you weren't thinking ahead you'd miss the opportunity to take flats.
I'd like to see the difference between a calibrated sub using both approaches to see if there is any visible difference.
I am pretty sure not as my calibrated frames are pretty perfect.
Greg.
|