What the colour matrix minimises: average across all patches (default), the single worst patch, or a chosen subset.
ALSC (lens shading)
Lux
Anchors the lux calibration on the single capture closest to this lux level (default 1000).
Robust average of luminance-per-lux across all captures — less hostage to any one image. Median resists a cluster of similar captures (e.g. several of one illuminant) better than the trimmed mean; both spread per-illuminant error across the set.