View Full Version : Video Frame Counting

12-20-1994, 06:58 AM
Sorry for such a newbie question, but we had an occassion to
try to verify a photosensor-based system for measuring finger
velocities while subjects stroked textured plates by comparing
the output to video frame counts taken simultaneously. The two
measures differ quite consistently by 6%. How stable is the 60
frame per second rate of a standard video camera? Is there an
internal oscillator or clock that is more stable than the power
line frequency? There are other potential sources for error,
but I wanted to know if I could discount the frame rate as a
possibility. Thanks.