In the Siril preprocessing tutorial at free-astro.org the following statement appears in a WARNING section:
“… However, applying dark optimization makes things different by multiplying masterDark by a coefficient factor not equal to 1. In this case, you must subtract masterBias from each dark frame.”
I understand the initial part of the statement (dark frame had dark signal + bias signal), what I don’t follow is the “… applying dark optimization…”
- Where and how is dark optimization done?
- How is the coefficient factor arrived at? (calc. automatically, chosen from a range of suitable values, …?
- WHY is dark optimization done?
(I’m using a Fuji mirrorless (RAF raw files) and Siril 0.9.12 on a Mac (Catalina))