All of this was still pinned to physical videotape transports and constant frame rates.
Once we shifted to high definition, an additional frame rate category of 59.94fps was added to the mix. (I’ll skip the field versus frame, interlaced versus progressive scan discussion.) Motion picture films captured at 24.0fps were transferred to video at the slightly slower rate of 23.976fps (23.98) in the US and converted to 29.97 by employing pulldown – a method to repeat certain frames according to a specific cadence. Once color technology was established, the standard record, playback, and broadcast frame rates became 29.97fps and/or 25.0fps worldwide. Variable-speed recording wasn’t possible using tape transport mechanisms. With the advent of videotape recording, the television industry was locked into constant recording speeds. There are modern film cameras that include controlled mechanisms to still be able to do that today – in production, not in post. While manual film cranking seems anachronistic in modern times, it had the benefit of in-camera, variable-speed capture – aka speed ramps. That characteristic motion is because they are no longer played at their intended speeds. One by-product of this shift is that the projection of old B&W films gained that fast, jerky motion we often incorrectly attribute to “old time movies” today. With sound, the default frame rate shifted from 18 to 24fps. If the camera was cranked slower than 18fps (undercranking), the motion was sped up. If the camera was cranked faster than 18fps (overcranking), then the playback speed during projection was in slow motion. Prior to the introduction of sound, the correct frame rate was 18fps. A good camera operator was partially judged by how constant of a frame rate they could maintain while cranking the film through the camera. The earliest film cameras required the camera operator to manually crank the film mechanism – they didn’t have internal motors. The concept of overcranking and undercranking in the world of film and video production goes back to the origins of motion picture technology.
0 kommentar(er)
