Light Calibration - Dark Optimization

[DMouse]

Hi, recently I had noticed that if I didn't have enough subs, or didn't get  enough dithering then I would get lots of hot pixels, even with Dark frames being used. Just as a trial, last nights imaging run, I unchecked the Dark optimization in the Calibration routine. Well the hot pixels are all but completely gone? My Master Dark is temp matched to the lights anyway, with about 15 to 20 subs for each Master Dark, in the Darks Library.
I thought optimization would improve things, not make them worse?

Here are 2 different stacks from last night. Just calibrated one with optimization the other without.

Camera was an ATIK383L+ mono, with Baader Ha filter.

[pfile]

this is normal - what PI does is scale the master dark until the total noise in the calibrated frame is minimized.

this may lead to hot pixels being left over, since they get scaled too, but they don't obey the same "rules" as the non-hot pixels in the image.

you can use CosmeticCorrection to clean up these left-over hot pixels. CC takes a dark as reference to identify the pixels that need help, but you can control how many pixels it actually works on with a slider.