Instruction manual

Marlin Technical ManualV.2.7.0
150
Controlling image capture
The following screenshot shows an example of broadcast commands sent with
the Firedemo example of FirePackage (version 1V51 or newer):
• Line 1 shows the broadcast command, which stops all cameras connected
to the same IEEE 1394 bus. It is generated by holding the Shift key down
while clicking on Write.
• Line 2 generates a broadcast one-shot in the same way, which forces all
connected cameras to simultaneously grab one image.
Jitter at start of exposure
The following chapter discusses the latency time which exists for all CCD models
when either a hardware or software trigger is generated, until the actual image
exposure starts.
Owing to the well-known fact that an Interline Transfer CCD sensor has both a
light sensitive area and a separate storage area, it is common to interleave
image exposure of a new frame and output that of the previous one. It makes
continuous image flow possible, even with an external trigger.
CMOS This is different to the way the CMOS sensor of the Marlin F-131 works: the
image sensitive area is also the storage area, which means that it cannot be used
for the integration of the new frame until it has been read out.
Continuous image flow is thus only possible with the so-called rolling shutter.
Asynchronous image acquisition only makes sense with the global shutter; lead-
ing to a non-interleaving exposure - readout - exposure sequence. For every
exposure cycle the sensor is completely reset so that the camera needs to be
idle.
CCD For the CCDs the uncertainty time delay before the start of exposure depends on
the state of the sensor. A distinction is made as follows:
Figure 75: Broadcast one-shot