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These are user-supplied measurements of the horizontal and vertical distances in the video camera's field of view. These distances must be measured empirically as they depend on the combination of the magnification in the optical system and the size of the camera's sensor. They are readily measured using a micrometer, or moving the stage or a pipet with a calibrated manipulator.
NOTE - failure to specify the span values will result in an error message, and the mapper will not work properly.
Phase Lag
Used for AOD scanners.
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