The snap function is a high level funtion that creates buffers, takes a picture and releases the buffer. It in not very efficient for continuous acquisition. I would look at either the "Grab", "Sequence", or "Ring" shipping examples. The Grab is designed more for a continuous acquisition, it takes images as quickly as possible and returns them to be viewed. The Sequence and Ring acquisitions actually set up extra buffers to help ensure that no frames are missed. Sequence is for a finite number of frames, and Ring is for continuous (it loops back to the beginning of the buffer list when complete). These exampes can all be found in your "...\National Instruments\NI-IMAQ\Sample\MSVC\" directory on your computer.