This is one of the areas where algorithms are still in flux and calibration methods are not fully mature.
Differential throughput of lenslets. Scattered handful of low throughput lenslets, plus a regular grid pattern due to artifacts from the lenslet manufacturing photolithography.
Use ‘Divide by Lenslet Flat Field’ primitive with a relevant lensletflat file.
Currently done via code not yet integrated into the pipeline
Marshall Perrin, Patrick Ingraham