SIGMA LBA-708 - Manual (Page 103)

3.6.2 What Disables Ultracal!
Ultracal will become DISABLED if certain data collection conditions, that were in effect when the
Ultracal operation was executed, are no longer in effect. In all cases, these conditions are the result
of an operators change to the spatial acquisition settings. The DISABLED condition will occur if you
make changes to:
• The Hardware Zoom.
• The Hardware Pan location.
• The Camera Type or Resolution setting.
• The Camera Electronic Shutter setting.
• The Video Gain and/or Black Level settings.
3.7 AutoExposure!… Menu Action Item
This menu item is only enabled when certain types of cameras are connected. These cameras must be
fitted with a remote controllable electronic shutter. From versions 4.XX, only analog cameras with
remotely controlled shutters, such as: Pulnix TM-745, TM-765, TM-6, and TM-7, will be supported. In
the future we intend to add additional camera types that feature electronically controlled exposure
times, adjustable gain settings, and programmable electronic shutters.
Note: This feature is only available when operating with the Trigger Mode set to CW. It is disabled in all Pulse
modes.
3.7.1 AutoExposure! Operation
When this menu item is enabled it indicates that your camera selection is set for a camera with some
type of remotely controllable shutter or exposure timing and that your Trigger Mode is set to CW. If
you click on this menu item the LBA-PC application will attempt to automatically set the camera
shutter or exposure to a value appropriate for the amount of power incident upon your camera’s focal
plane array. The AutoExposure algorithm will start with the maximum exposure time and reduce
the exposure until the peak fluence is less than 90% of the camera’s dynamic range. If it reaches the
shortest exposure time allowed by your camera and can not meet the above criteria, it will leave the
exposure setting at this minimum value and request that you attenuate your laser using some external
means. I.e., either place additional ND filters into the laser beam path or reduce the output power of
your laser source. After attenuating your laser it may be a good idea to rerun the AutoExposure
operation.
3.7.2 AutoExposure Interacts with Ultracal
With most any camera that has a programmable shutter or exposure, a change of the
shutter/exposure setting will produce a change in the camera black level setting, and therefore may
disable ultracal, which will cause the Ultracal indicator to turn red. It is therefore recommended that
any changes to the AutoExposure are followed by an Ultracal operation.
Operator’s Manual LBA-PC
Doc. No. 10654-001, Rev 4.10
103