How can I use integration times longer than 6700 ms?
There is no upper limit on the integration times used with the Shad-o-Box camera itself. However, the integration time is usually controlled by a counter on the frame grabber board, which typically has a limit of a few seconds before it rolls over. For the PXD1000 frame grabber this limit is 6700 ms. In order to use longer integration times, you need to either connect to the external trigger input on the camera, or activate the frame grabber trigger separately via custom software (this latter approach is beyond the scope of this tutorial). Simply connect a cable to the Ext. Sync SMA input on the camera front panel and supply a TTL or 5 V pulse each time you want to read out the sensor. The pulse length should be between 10 and 100 ms. The period between pulses determines the integration time. Remember that you need to disable the trigger from the frame grabber when doing this otherwise the two signals will compete with each other. You can also use the same technique with our Shad-o-Sna
