3.5.2
Rolling Shutter Mode
•
Line by line integration state
•
Line by line transfer and readout
Integration of next line is delayed by readout time of one line
Figure 74: rolling shutter mode - schematic
Because of the sequential start of the exposure, the rolling shutter mode may introduce artifacts effect if objects move. In the direction
of the lines (horizontal) the image will be sheared. When moving in vertical direction, the object may appear longer or shorter. When the
exposure is longer also motion blur may occur
Figure 75: rolling shutter mode image of a horizontally moved object
Figure 76: rolling shutter mode image of a horizontally moved object, long exposure time
Rolling shutter artifacts may be prevented by using a flash or stroboscopic light. The flash or strobe must occur when all lines are exposed
simultaneously. The exact timing depends on sensor type and readout timing. In Rolling shutter mode all lines are triggered consecutively,
and a strobe must be timed so that it does not start before all lines are open. The delay can be calculated from the highest frame rate and
is 1/fps. The strobe must also end before the first lines are closed again for exposure, which sets a lower limit for the exposure time, as
can be seen in the figure above.
Figure 77: rolling shutter mode with flash - schematic
XIMEA Technical Manual, Version: v240108
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