Basic CT Blunder #37:
Pretending to understand film, video and frame rates.
(AKA "Doing a Jack White")
The clock on the video can't be used to measure or prove anything.
It has nothing whatsoever to do with the original film or its frame-rate.
It is a timer being shown on playback of a VHS recording.
It isn't burned into the recording, nor is it a time code.
Transcribing VHS/VHSC/8mm/Hi8/miniDV tapes onto DVD is part of what I do for a living, so I can speak to this with some authority. For the record, I use an ex-TVNZ Panasonic AG-7650-P commercial grade VHS/S-VHS tape deck to a DataVideo DN-400 HDD recorder (also ex broadcast), and then the resulting video files are sent to a PC for burning to a DVD.
First Mistake this claimant has made
Any tape of the Apollo Launches, at least the early ones, will have been filmed on silver halide 8mm or 16mm film and transferred to VHS tape. This process is fraught with potential errors. Film projectors and telecines of the era were mechanically timed, and the adjustment was usually a tension lever or an adjustment screw. Nominally, the frame rate for 8mm (one row of sprocket holes) is about 16 f/s, Super 8 (two rows of sprocket holes) is about 18 f/s but there is no guarantee that whoever transferred this had the projector frame rate set correctly. It was quite common to operate projectors like these at slightly above nominal frame rate to avoid
"frame flicker". 16mm was run at 24 f/s so flicker would not normally be a problem.
However, worn sprocket holes, worn belts, motors and mechanical parts in the projector itself and a problem called
"gate weave" can introduce timing errors. In fact, when people talk about a film running at
"24 frames per second" that does not necessarily mean that each frame is displayed at 1/24th of a second intervals. The timing between frames can vary as much as 5%, and most viewers wont notice.
Second mistake claimant has made
Even assuming that the Film > VHS transfer was made accurately with all the timing as close as possible, there is still the problem of
"tape stretch" As a VHS tape is played, rewound, fast forwarded and paused over a number of years it stretches. A time code is encoded on the tape at the time it is recorded, and as the tape stretches, the time code itself is expanded... think of the time code as a series of marks recorded on the tape at one second intervals. VHS tape (in SP mode) runs at 33.3 linear mm per second (mps), so the marks will be at 33.3 mm intervals. A VHS tape can stretch by 15% or more and when that happens, the marks will now be at 38.3 mm intervals, but the tape is still running a 33.3 mps so your 1 second markers take more than 1 second between passes over the playback head. I have seen this for myself; I reset the time counters on both the VHS tape deck and the HDD recorder to 0:00:00 at the beginning, and by the time it has transcribed a 3 hour tape, the differential between the two counters can be as much as 30 minutes!!!
Trying to measure the speed of an object on old VHS tape, especially when the footage has been transferred from film, can yield no usable or meaningful results. Timing errors will be well beyond the ranges of anything you are trying to measure.
