Super Motion System
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Super Motion System By L. J. Thorpe, T. Nakamura, and K. Ninomiya A radically new television field-acquisition system designed to enhance The quality of a given picture the capture of motion is described. The Super Motion system is com- frame. The spatial resolution of that prised of a new genre of color television camera and a new VTR system. frame, which is obviously adversely The motion judder and image blur associated with conventional TV impacted by the fact that the subject is in motion for the brief period during pictures when played on a standard slow-motion recorder have been which the frame is being exposed or overcome. This is accomplished by shooting the scene with a camera scanned, and complicated further by whose frame rate is three times as high as that of a normal 525/30 the finite integration time of today’s camera. New technologies incorporated in the system - mixed-field photoconductive pickup tubes. pickup t ubes,f iber-optic transmission, digital processing and standards These two factors contribute di- conversion, and high-speed C-MOS digital LSI chips to encode RGB to rectly to the subjectively disturbing NTSC-are described. phenomena that mar conventional Type-C slow-motion playback. The specific symptoms are: ince the introduction of the Type- Development of the Super Motion Staccato motion. A direct result S C 1-in. videotape recorder, slow- System” at the 126th SMPTE Tech- of inadequate temporal resolution motion video replay has gained wide nical Conference in November 1984. and the repeat field mechanism em- popularity by permitting close exami- This paper dealt in some detail with ployed in Type-C slow-motion play- nation of movement in sports, science, the theory of the special VTR em- back. and drama. Increasingly, it is even ployed. The emphasis of this article Picture blur. Associated with the used as a special effect in commer- will be on the special Super Motion frame rate of the taking camera and cials and drama. Dynamic tracking camera. the finite integration time of the (DT) technology (essential to this fa- pickup devices used. cility) has become an indispensable The Slow-Motion Problem It has long been recognized that the element of this format. This slow-mo- poor reproduction of movement (typi- tion ability is eagerly sought within While adding immeasurably to the fied by the erratic or staccato nature smaller-format systems, such as 3/4-in. production capabilities of today’s of this motion), particularly when the and the new l/z-in. VTR, the technical quality of conven- playback is substantially slowed In the film domain, the problem is tional 1- in. Type-C slow-motion play- down, is subjectively a much more tackled by increasing the shutter back is fundamentally flawed. TV disturbing aspect. The associated speed to multiples of the normal 24 cameras shoot at a fixed field rate of problem of picture blur actually alle- frames/sec (camera frame rate). 60 Hz, and thus deliver to the VTR a viates this problem by masking the When the film is subsequently pro- finite number of video “snapshots.” jerkiness via the integration or blur- jected at a fixed speed of 24 frames/ This is a relatively slow taking rate, ring phenomenon. In playback of sec, the motion is reproduced at a rate particularly when fast motion is in- many sports activities, the split-sec- proportionally slower (by the same volved, and much motion resolution is ond relative motion (as in racing) or multiple as the shutter was increased) inherently lost. the beauty of form (as in gymnastics) but with the same quality as would be The Type-C VTR can be controlled is primarily impaired by the poor time seen in the projection of a normal- to play back the recorded tape at any resolution of the system. speed picture. The viewer is looking at linear speed between still-frame and The Super Motion system was de- all of the original high-speed frames, normal speed of 24.4 cm/sec. To re- veloped specifically to improve the over a longer period of time, and thus play in slow motion, the appropriate first of these problems. That is, it is sees slow motion with higher tempo- intermediate speed is set, and for the designed to substantially enhance the ral resolution. VTR to produce a standard 525/60 fluidity of the slow motion (also inci- The Super Motion system was de- NTSC output, the video head must dentally reducing the motion blur), veloped to solve a specific problem trace the same track multiple times rather than to improve the clarity of a associated with conventional slow- (this multiple varying according to stop-action freeze-frame picture. motion playback of television record- speed of slow-motion replay). The ings. Sony Broadcast Products pre- limited number of frames recorded sented a paper entitled “ T h e initially is thus further reduced, caus- Fundamentals of the Super ing increased motion impairment. Motion System There are two important aspects re- The Super Motion system emulates Presented at the 19th Annual SMPTE Television Conference in San Francisco (paper No. 19-20) on lating to the impaired quality of the high-speed photography in the video February 16,1985. L. J. Thorpe (who read the paper) reproduced slow-motion image: domain. This is accomplished by is affiliated with Sony Broadcast Products Corp., Tea- 0 The resolution the motion it- shooting the scene with a camera op- neck. N.J. T. Nakamura and K. Ninomiya are with of Sony Communications Products Group, Atsugi. Ja- self. The clarity and smoothness of erating at a frame rate that is three pan. This article was received February 6, 1985, and the movement, which is purely a func- times as high as that of a normal TV also appears in Components ofthe Future. published scan rate (30 frames/sec). The Super SMPTE, 1985. Copyright 0 1985 by the Society of tion of the system’s temporal resolu- Motion Picture and Television Engineers, Inc. tion. Motion camera runs at 90 frames/ 896 SMPTE Journal, September 1985 sec. In '/3o sec, it therefore photo- and it fits nicely with the generally ments in the spatial resolution, for graphs three sequential video frames accepted 4.2 MHz for the NTSC sig- example, to double the horizontal and in place of the one single frame cap- nal. vertical spatial resolution as in the tured by a conventional camera. If an In the Super Motion camera, all 1125/60 system. That same band- object is in motion, three snapshots of parameters are assumed to remain width, however, can just as well be the progress of that motion are cap- the same, except fF which now be- applied to the third important dimen- tured, rather than just one, in '/30 sec. comes 90, and this produces: sion of TV, the temporal or time di- The BVP-3000 Super Motion cam- mension. This is the premise of the era scans 525 television lines at a 90- fmax = 112 X 0.7 X 1.33 X 525 X 90 Super Motion camera. The spatial Hz frame rate, or 180 fields inter- X I resolution is essentially that of today's = 12.6 MHz laced 2:l. To record subsequently this NTSC signal, and all of the band- unusual signal and play it back as a The significant fact is that there is a width is employed to sustain the de- standard 525/30-Hz NTSC signal, so proportional relationship between the mands of the higher frame rate (Eq. that it will deliver an appropriate sig- frame rate of a camera and the band- 1). Thus, in its deployment of band- nal into the existing TV signal, re- width of which it must be capable. In width, the Super Motion system is a quires the process of standards con- conventional TV color cameras, the variation on the theme of high defini- version. The 90-Hz frame rate must originating RGB set is actually wider tion - high temporal definition. be converted down to the 30-Hz stan- than the 3-dB minimum of 4.2 MHz In discussing the special processing dard. This conversion is accomplished for the NTSC system, being more required, we refer to a set of three in the camera control unit (CCU) pri- typically 6 or 8 MHz to allow proper high-speed fields occupying the same or to recording. aperture-correction schemes to be time duration as a TV field in a con- The elevation of the camera frame employed and to produce full band- ventional 525/60 camera. Each of the rate, while keeping the number of width for picture processing, etc., high-speed pictures is expanded in scanning lines constant at 525, has within a studio. The Super Motion time in the standards conversion pro- important repercussions on two key camera has been designed with a cess, and is then separated into three facets of camera design: pickup de- bandwidth closer to 18 to 20 MHz. individual pictures. Each of these re- vice technology and bandwidth. The In one sense, the Super Motion constructed fields is recorded in real bandwidth consideration is important camera is a high-definition camera. time on a specially designed high- because it forces us into the realm of All of the design techniques - the speed Super Motion VTR. The three high-definition television. wideband pickup requirements, high- original high-speed fields from the The minimum bandwidth required er scanning rates, and wideband camera totalled '/60 sec in time. Their to reproduce all of the information preamplifier and video processing - recorded time, on tape, now totals 3/60 within a specific TV standard is given are those required, for example, in an sec.