NTSC
[2] In 1953, a second NTSC standard was adopted,[3] which allowed for color television broadcast compatible with the existing stock of black-and-white receivers.
The NTSC/System M standard was used in most of the Americas (except Argentina, Brazil, Paraguay, and Uruguay), Myanmar, South Korea, Taiwan, Philippines, Japan, and some Pacific Islands nations and territories (see map).
In March 1941, the committee issued a technical standard for black-and-white television that built upon a 1936 recommendation made by the Radio Manufacturers Association (RMA).
Technical advancements of the vestigial side band technique allowed for the opportunity to increase the image resolution.
Other standards in the final recommendation were an aspect ratio of 4:3, and frequency modulation (FM) for the sound signal (which was quite new at the time).
Legal action by rival RCA kept commercial use of the system off the air until June 1951, and regular broadcasts only lasted a few months before manufacture of all color television sets was banned by the Office of Defense Mobilization in October, ostensibly due to the Korean War.
[citation needed] CBS rescinded its system in March 1953,[17] and the FCC replaced it on December 17, 1953, with the NTSC color standard, which was cooperatively developed by several companies, including RCA and Philco.
NTSC color encoding is used with the System M television signal, which consists of 30⁄1.001 (approximately 29.97) interlaced frames of video per second.
Matching the field refresh rate to the power source avoided intermodulation (also called beating), which produces rolling bars on the screen.
By the time the frame rate changed to accommodate color, it was nearly as easy to trigger the camera shutter from the video signal itself.
[29] The original 1953 color NTSC specification, still part of the United States Code of Federal Regulations, defined the colorimetric values of the system as shown in the above table.
[30] Early color television receivers, such as the RCA CT-100, were faithful to this specification (which was based on prevailing motion picture standards), having a larger gamut than most of today's monitors.
Starting in the late 1950s, picture tube phosphors would sacrifice saturation for increased brightness; this deviation from the standard at both the receiver and broadcaster was the source of considerable color variation.
As a consequence, the ATSC digital television standard states that for 480i signals, SMPTE C colorimetry should be assumed unless colorimetric data is included in the transport stream.
[33] Both the PAL and SECAM systems used the original 1953 NTSC colorimetry as well until 1970;[33] unlike NTSC, however, the European Broadcasting Union (EBU) rejected color correction in receivers and studio monitors that year and instead explicitly called for all equipment to directly encode signals for the "EBU" colorimetric values.
A triangular 60 Hz energy dispersal waveform is added to the composite baseband signal (video plus audio and data subcarriers) before modulation.
The film telecine process where a three-two pull down is utilized to convert 24 frames to 30, will also provide unacceptable results if the field order is incorrect.
This can be observed in PC-based video-playing utilities and is frequently solved simply by transcoding the video at half resolution and only using one of the two available fields.
Most analog NTSC television sets and monitors with a V-Hold knob can display this system after adjusting the vertical hold.
[citation needed] It was also found as an optional output on some LaserDisc players sold in markets where the PAL system is used.
The heterodyne color-under process of U-Matic, Betamax & VHS lent itself to minor modification of VCR players to accommodate NTSC format cassettes.
In January 1960, (7 years prior to adoption of the modified SECAM version) the experimental TV studio in Moscow started broadcasting using the OSKM system.
The OSKM abbreviation means "Simultaneous system with quadrature modulation" (In Russian: Одновременная Система с Квадратурной Модуляцией).
SECAM in particular was very robust, but PAL, while excellent in maintaining skin tones which viewers are particularly sensitive to, nevertheless would distort other colors in the face of phase errors.
Hue controls are still found on NTSC TVs, but color drifting generally ceased to be a problem for more modern circuitry by the 1970s.
For VHS videotape on the horizontal axis and frame rate of the three color systems when used with this scheme, the use of S-Video gives the higher resolution picture quality on monitors and TVs without a high-quality motion-compensated comb filtering section.
The Atari 800 and Commodore 64 home computers generate S-video, but only when used with specially designed monitors as no TV at the time supported the separate chroma and luma on standard RCA jacks.
The remaining lines were deliberately blanked in the original NTSC specification to provide time for the electron beam in CRT screens to return to the top of the display.
[55] Suitably equipped television sets could then employ these data in order to adjust the display to a closer match of the original studio image.
Many of these have switched or are currently switching from NTSC to digital television standards such as ATSC (United States, Canada, Mexico, Suriname, Jamaica, South Korea, Saint Lucia, Bahamas, Barbados, Grenada, Antigua and Barbuda, Haiti), ISDB (Japan, Philippines, part of South America and Saint Kitts and Nevis), DVB-T (Taiwan, Panama, Colombia, Myanmar, and Trinidad and Tobago) or DTMB (Cuba).
