Siril

Bias/offset

inherent noise of sensor Can be taken once and used for months Temp doesn't matter very much for most cams Take 20-40 frames with lens cap on, shortest exposure available, same ISO

Open Siril, set work dir, add all raws, convert (no debayer /!, keep all channels) Then stacking > median stacking, no normalisation

Dark

Thermal noise during or After shooting (temp important), same params but with lens cap on

Open Siril, set work dir, add all raws, convert (no debayer /!, keep all channels) basic: Then stacking > median stacking, no normalisation most optimal : average stacking with rejection, no normalisation, Winsorized sigma clipping (if rejection ends up > 0.5%, fall back to median stacking, no norm)

Lights

Simple photos of the object In siril, change dir, set seq name, convert WITH debayer Registration: registration method "Global star", else don't change settings

Comets

Sources

basics: https://www.youtube.com/watch?v=qYXd0rrAzjg pre-process: https://www.youtube.com/watch?v=RswLpEE7EZ4 https://free-astro.org/index.php/Siril:Tutorial_preprocessing