Snapshot Mode - Dalsa 4M30 User Manual

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Snapshot Mode

The Falcon 4M60 and Falcon 4M30 cameras include a feature called Snapshot Mode.
Snapshot Modes 1 and 2 allow the camera to produce usable images when intervals
between EXSYNCs are large (>200 ms).
Previously only snapshot mode 0 was available (no fast frame dump) which would
eventually result in a completely saturated 'first' image after a very long EXSYNC idle
period (seconds), as shown below.
By altering the internal timing, Snapshot Mode 1 performs a fast clearing of a frame
concurrently with integration. Thus, any dark current that caused elevated dark offset
levels, FPN or hot pixels, is cleared from the sensor prior to readout. The end result is that
the camera produces a usable first image.
With Snapshot Mode 1, please note that the timing of EXSYNC with respect to the
integration time has changed. The figure below illustrates Snapshot Mode 1 timing. The
difference is that the Integration Time, Z, is now equal to the EXSYNC high time, X, plus
the time it takes to clear the image, Y (plus 3.1 us of additional overhead). The total time
to clear the frame is Y (approximately 500 us). Therefore, the minimum integration time
in Snapshot Mode 1 is Y + 3.1 us. The exact value of Y is listed in the gcp screen as DUMP
TIME.
03-032-20044-01
First Frame Elevated Offset - efd 0
sem 4, External EXSYNC and exposure (smart EXSYNC)
Falcon 4M Camera Manual
DALSA