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6.4.5. Long Time Exposure
The exposure time is the interval between 2 ext. VD pulses sent to the VD input of the camera.
The exposure starts after input of the first ext. VD pulse, and ends after the next input of the
ext. VD pulse, which again starts a new exposure.
The long time exposure is a continuous process where each external VD pulse will synchronize
the camera, stop on exposure, start a new exposure and read out the previous accumulated
signal. The exposure can be selected in intervals of complete vertical timing periods (=792H)
This long time exposure mode operates in H non-reset mode. In H non-reset mode the external
VD signal and the internal HD signal are synchronized. The exposure will start at the first HD
pulse after the falling edge of the external trigger signal. See figure 14. for the phase
relationship between ext. HD and ext. VD pulses.
Mode setting and all other settings can be done via RS 232C control if rear switch SW1-10 is ON.
This mode can not be set by switch!
For details: refer to “7. Configuring the Camera”.
To use this mode:
RS
Set function: Trigger mode to “Long Time Shutter”
TR=4
Polarity and other functions
Input:
Ext VD on pin 7 on 12 pin con. (Or 1 on 9 pin ). 4.0 Vp-p ±2.0V.
Ext. HD in on pin 6 on 12-pin connector. 4.0 Vp-p ±2.0V.
(If used).
Important notes on using this mode
•
External sync system should follow the camera scanning system.
•
External VD and HD phase relation should follow as shown in fig. 10.
•
Depending of the temperature, it is not recommended to use integration >2 seconds.
Fig. 19. Vertical timing for Long Time Exposure
