mysterious dark current

[chiahaoliu]

preamble: under no beam, I want to test reliablity of my dark substraction approach

dark current substraction works fine with 'stable' motor, i.e. no spatial positioner moves (confirm this by doing dark substraction to dark images and see if intensity at every pixel goes to zero)

However, when doing dark current subsraction with scans that move motors like th_cal. Dark correction is not working properly anymore. Over/under correction happens.

One possible reason can be that area detector accidentally includes residual signals during motor motion, therefore it reads more/less values then its exposure time. Namely, real_exposure_time = assigned_exposuretime + (motor_moving_time)

[chiahaoliu]

I leave dark_correct as an option of save_tif therefore user can always have second options when he sees weird images afer darkl correction