There are many possible reasons for this behavior, the reasons depend somewhat on the type of camera you are using and the frame grabber. If you are using an analog camera in interlaced mode it is possible that you are somehow reading the individual frames one on top of the other instead of correctly interlaced. If it is a digital camera, it may be that data is being interpreted incorrectly - perhaps a vertical synch is being missed. Do you see the same behavior from within Measurement and Automation Explorer (MAX)? If you are able to reproduce the behavior there, I would call National Instruments and discuss the issue with one of their Applcations Engineers. As a first step you might also look at upgrading your NI-IMAQ driver to the latest version (2.6) from the <
a href="http://digital.ni.com/softlib.nsf/websearch/50F6D6F1094A033586256D52006146E0?opendocument">NI Driver Download Site.