Search for Richard Leadbetter's posts on this forum. It was here that the method was discussed and finalised. There may have been some updates since then, of course, with increases in processing power enabling a better sample of points, although IIRC, the final solution was very robust and wouldn't really need improving.Anyhow, I would like to know about the kind of equipment and methodology DF uses to count frames, anyone have a link? that would be greatly appreciated.