Default: 40 ms
This setting is only used for Bulb HDR or Bulb Ramping modes. This setting must be calibrated before using any of the modes above. Default value of 40 milliseconds is adequate for some cameras, but introduce exposure inaccuracy in Bulb HDR / Bulb Ramping modes.
Calibration requires a compatible shutter cable and a Bulb Ramping / Bulb HDR Assist cable to be connected. See Promote Control Setup section for more information on how to calibrate this value.
If you change the camera model for Bulb HDR or Bulb Ramping, this value will need to be recalibrated. Changing your camera lens will not affect this setting though - so simply changing your lens will NOT require recalibration.
The calibration process takes just a few seconds, and is therefore recommended to be performed before starting a Bulb HDR or Bulb Ramping session.