Stacking from multiple sessions

[FuriousRabbit]

What is the best way to go about combining captures from different nights?

The way I'm thinking to go about this is: combine the lights and darks from 'night a' to create the master light 'master a'. Combine the lights and darks from night b to create the master light 'master b'. Align and combine 'master a' & 'master b' to create pre-processed 'master c'. Finish post processing on 'master c'

With different temperatures and angles during my capture I would think this is the best way to combine lights and darks from different sessions.

[pfile]

if the temperatures do not differ too much, just turn on dark optimization and calibrate/register/integrate them all at once.

the only reason i ever found to do night-by-night is because my DSLR exhibits some banding, and once the images are rotated it becomes impossible to remove the banding in the stack.

[FuriousRabbit]

if the temperatures do not differ too much, just turn on dark optimization and calibrate/register/integrate them all at once.

What exactly does dark optimization do?

[pfile]

it scales the dark (multiplies the pixel values by some factor). ImageCalibration determines the scaling factor by (internally) trying different scaling values until it finds the value that minimizes the noise in the final result. as such it does not care about the temperature or duration of the dark or light frames.

if you want to scale the dark you must use a master bias frame during calibration.

of course, it can only do so much, so your master dark temperature should be reasonably close to the lights. dark current is exponential in temperature but linear in time, so more closely matching temperature is more important than matching exposure times.