24-06-2020, 11:57 AM
In the 1950s a single Ampex VTR was a huge investment. I don't think the first generation machines even had the capability of doing a proper assemble or insert edit. With physical splicing it was actually even worse than just cutting the tape. Because the audio is a few inches away from the video you had to lay the sound off to an ordinary 0.25" audio R-R recorder and dub it back afterwards.
Timecode was a brilliant invention that has caused massive grief in 60Hz countries. When NTSC colour was introduced, for some reason to do with chroma to sound crosstalk they changed the frame rate from 30Hz to 29.97Hz. They could have shifted the sound carrier instead but this could have required all TV owners (monochome and colour) to have their sound IF retuned. This wasn't a problem until timecode was invented some years later. Coping with a frame rate that isn't an integer meant using drop-frame numbering which in turn has residual errors in longer recordings.
Even today, all the 30Hz related HD standards are specified in 30Hz and 29.97Hz versions. Even the 4K standards. Even more strangely, the 24Hz related HD standards have 23.98Hz versions. Yuk.
Timecode was a brilliant invention that has caused massive grief in 60Hz countries. When NTSC colour was introduced, for some reason to do with chroma to sound crosstalk they changed the frame rate from 30Hz to 29.97Hz. They could have shifted the sound carrier instead but this could have required all TV owners (monochome and colour) to have their sound IF retuned. This wasn't a problem until timecode was invented some years later. Coping with a frame rate that isn't an integer meant using drop-frame numbering which in turn has residual errors in longer recordings.
Even today, all the 30Hz related HD standards are specified in 30Hz and 29.97Hz versions. Even the 4K standards. Even more strangely, the 24Hz related HD standards have 23.98Hz versions. Yuk.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
