Gideon asked me to help with your questions regarding JVC DVL9600 or DVL9800 camcorders in high speed mode.

I think your analysis of the pixel dimensions for these camera models is basically correct.   Assuming NTSC, one starts with a frame which is 720x480. Separating the two fields which are 1/60 sec apart results in a whole field size of 720x240. Then if one considers 120Hz with horizontal panels the optimal size would be 720x120, or vertical panels 360x240. At 240 hz the optimal panel size would be 360x120.

As a practical matter, JVC does not split the panels optimally. In practice the real panel sizes approximately are:

            120Hz Horizontal   720x240

            120Hz Vertical   300x240

            240Hz   300x185 

 

The two cameras in question are great cameras. They offer much higher that standard image rates of a very affordable price. This makes them a very attractive choice for biomechanical analysis. However there clearly is a tradeoff involved, higher image rate for lower resolution. One can get both the higher image rate without loss of resolution but only at a high price.

I hope this helps.

Jeremy Wise, PhD

Dir R&D