Camera modes of operation 95
rate is the reciprocal of the sum of the exposure time and the frame transfer time.
The camera sets an upper limit on the exposure time but, as opposed to continuous
mode, the exposure time can be much longer than the frame transfer time.
❖ Some cameras however, are capable of integrating while outputting the previous
frame. Refer to the documentation for the camera for further information.
Y The signals involved in this mode are the video output and synchronization
signals. As with continuous mode, these signals might be combined with video
R data (composite) or separate digital synchronization signals can be used.
The following illustrates the timings for pseudo-continuous mode.
INA 005 camera
video signal1
sync*2
pixel clock*3
frame grabber
IM 2 frame0
L Y exposure: frame 0
transfer: frame 0
non-interlaced video signal
E A * optional signal
1. analog or digital
2. bi-directional and separate
vsync in some cases only
PR19 M 3.internalorexternal
exposure: frame 1
frame 1
transfer: frame 1
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