Xref: utzoo comp.graphics:6820 rec.video:7492 Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!sun-barr!newstop!sun!vector!poynton From: poynton@vector.Sun.COM (Charles A. Poynton) Newsgroups: comp.graphics,rec.video Subject: Re: HDTV and ATV Glossary (TN32) Summary: 24 Hz is sufficient for motion rendition. With modern framestore technology, the issues of motion rendition and flicker can be separated. Keywords: 525/59.94, 625/50, NTSC, PAL, SECAM, Component, Composite, Message-ID: <121076@sun.Eng.Sun.COM> Date: 11 Aug 89 22:48:48 GMT References: <120919@sun.Eng.Sun.COM> Sender: news@sun.Eng.Sun.COM Lines: 53 A correspondent writes: >> p.s. 1250/24, 2048-by-1152, 74.25 MHz. Dare to be square! > Why frame rate of 24? Given there is movement in the film industry to > move to 30, ... A few people in Hollywood proposed 30 Hz film, and SMPTE had a study group on it, but there was never any popular support behind the idea. Among other things, - 24 Hz is quite sufficient for motion rendition, - 30 Hz consumes more film stock (tied to the price of silver!), - international program exchange would suffer (3 G$ U.S. trade surplus in exported movies), - few commercial projectors are capable of 30 Hz without modification. All in all, just no good reason to do it. > ... why burden TV with a slower rate. Ah, wait a minute here, we want to burden TVs with a slower rate because we can't afford the bandwidth to raise it! Keep in mind that in the olden days one had to choose a frame rate which simultaneously satisfied motion rendition AND flicker constraints. The fact of living rooms being (on average) brighter than movie theatres forced television in 1941 to adopt a 30 Hz frame rate. With framestore technology, these issues can be separated. > Look to the future, not the past. The future is now. Sony and Hitachi are recording digital HDTV on one-inch magtape at 1.188 Gb/s, a full order of magnitude higher than the best available U.S. technology (the Ampex D-2 machine at 114 Mb/s). Sony are shipping 2k-by-2k Trinitrons when the best Zenith can do is 640-by-480. That's a factor of eight. Sure we could glibly standardize double the horizontal and vertical resolution of HDTV but that would be a pointless theoretical exercise unless we can build the stuff. The best way for us to get back into building the stuff is to exploit the commercially-available Japanese technology -- now. C. ----- Charles A. Poynton Sun Microsystems Inc. 2550 Garcia Avenue, MS 8-04 415-336-7846 Mountain View, CA 94043 "There's no offense where none is taken." -- Ancient Chinese proverb -----