However, your assertion of an error bandwidth of .04 seconds accounts only for camera error. What about clock error? This must be factored in, as noted in my just-preceding post. Once we do this, we get a single-measurement bandwidth of about ± .06 seconds, and this applies at each measurement point. Since two measurements are required to evaluate drift (that is to get a spy value), the actual error bandwidth of the change, or drift, calculation will be about ± .08 - .09 seconds. Given this fact, any estimate of spy using a single observation at each time point with the Video Method will produce a total error bandwidth of about ± 31 seconds for a one-day assessment of spy, and about ± 4.5 seconds for a spy estimate based on a one-week time period--that is, taking the offset from the atomic clock at Time 1 and then again at Time 1 + 7 days and using the change between the two as an estimate of drift, prorated to an annualized spy value.