CLASS RACER FORUM - View Single Post - Richardson Barone, winner of the U.S. Nationals ? (Redirected. May affect everyone)

Larry Sullivan · 09-11-2007, 05:36 PM

Video frames are misleading - the top of the frame was scanned 1/60th of a second before the bottom of the screen frame (30 frames per second, two interlaced scans per frame), so the car in the nearer lane always appears to be ahead of its actual position because it was scanned later. In other words, you need a snapshot, not a vertically scanned video image, in order to get a true picture, or you need a video system that scans a lot quicker than 30 frames per second. The MOV in this example (.0047) is much smaller than the video frame uncertainty (.0167). And, given the angle of the finish stripe in the frame, the camera was not perpendicular to the track, further distorting the image.

09-11-2007, 05:36 PM	#9
Larry Sullivan Member Join Date: Mar 2003 Location: Baytown, TX Posts: 340 Likes: 0 Liked 3 Times in 1 Post	Re: Richardson Barone, winner of the U.S. Nationals ? (Redirected. May affect every Video frames are misleading - the top of the frame was scanned 1/60th of a second before the bottom of the screen frame (30 frames per second, two interlaced scans per frame), so the car in the nearer lane always appears to be ahead of its actual position because it was scanned later. In other words, you need a snapshot, not a vertically scanned video image, in order to get a true picture, or you need a video system that scans a lot quicker than 30 frames per second. The MOV in this example (.0047) is much smaller than the video frame uncertainty (.0167). And, given the angle of the finish stripe in the frame, the camera was not perpendicular to the track, further distorting the image.