You are probably aware that a video frame consists of two interlaced video fields. The first field contains all the even numbered lines, and the second all the odd numbered lines. A similar averaging process is used for the odd field. The net result of this is that the vertical resolution is less than the number of rows of pixels in the CCD chip. The reason for doing this is simply that the electronics required are much easier than having each output line corresponding to a single row of pixels on the CCD chip.
Some cameras however have the option of having a single row of pixels per output line.
For example the Cohu 4910 and 4990 series and the Sony XC-77RRCE are monochrome cameras which may use one row of pixels for each output line, and the JVC F30 is a 3CCD colour camera with the same ability. The end result is that for a stationary image the vertical resolution is much higher than a standard camera. The higher light levels that will be required with the faster shutter probably rule out the use of this mode for work with light sheets. Another problem with standard video cameras is that the electronic shutter opens once per field, i.e. 50 times per second. For rapidly evolving flows this can cause a problem.