Sigma LBA-400 AutoExposure!… Menu Action Item, What Disables Ultracal, AutoExposure! Operation

3.6.2What 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DISABLED if certain data collection conditions, that were in effect when the Ultracal operation was executed, are no longer in effect.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.

3.7AutoExposure!… 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.

3.7.1AutoExposure! 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.

3.7.2AutoExposure 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	103	LBA-PC
Doc. No. 10654-001, Rev 4.10