field-sequential color system

According to television historian Albert Abramson, A. A. Polumordvinov invented the first field-sequential color system. Polumordvinov applied for his Russian patent 10738 in 1899. This system scanned images with two rotating cylinders.

{{Cite book

| first1 = Albert

| last1 = Abramson

| title = The History of Television, 1880 to 1941

| publisher = McFarland & Company

| location = Jefferson, North Carolina

| date = 1987

| pages = 24, 277

| isbn = 978-0899502847

| url = https://books.google.com/books?id=hxlTAAAAMAAJ

}} A later German patent by A. Frankenstein and Werner von Jaworski described another field-sequential system. Like the CBS System, this patent included a color wheel. Frankenstein and Jaworski applied for their patent 172376 in 1904.

John Logie Baird demonstrated a version of field-sequential color television on July 3, 1928, using a mechanical television system before his use of cathode ray tubes, and producing a vertical color image about 4 inches (10 cm) high. It was described in the journal Nature:

:The process consisted of first exploring the object, the image of which is to be transmitted, with a spot of red light, next with a spot of green light, and finally with a spot of blue light. At the receiving station a similar process is employed, red, blue and green images being presented in rapid success to the eye. The apparatus used at the transmitter consists of a disc perforated with three successive spiral curves of holes. The holes in the first spiral are covered with red filters, in the second with green filters and in the third with blue. Light is projected through these holes and an image of the moving holes is projected onto the object. The disc revolves at 10 revolutions per second and so thirty complete images are transmitted every second—ten blue, ten red, and ten green.

:At the receiving station a similar disc revolves synchronously with the transmitting disc, and behind this disc, in line with the eye of the observer, are two glow discharge lamps. One of these lamps is a neon tube and the other a tube containing mercury vapor and helium. By means of a commutator the mercury vapor and helium tube is placed in circuit for two-thirds of a revolution and the neon tube for the remaining third. The red light from the neon is accentuated by placing red filters over the view holes for the red image. Similarly, the view holes corresponding to the green and blue images are covered by suitable filters. The blue and green lights both come from the mercury helium tube, which emits light rich in both colors.Alexander Russell, Nature, August 18, 1928.

Baird demonstrated a modified two-color version in February 1938, using a red and blue-green filter arrangement in the transmitter; on July 27, 1939 he further demonstrated that colour scanning system in combination with a cathode ray tube with filter wheel as the receiver."[http://www.earlytelevision.org/baird_mechanical_color.html Colour Television: Baird Experimental System Described]", Wireless World, August 17, 1939. By December 1940 he had publicly demonstrating a 600 line version of the system.{{Cite web |title=High Definition Colour Television, 1940–1944 – Bairdtelevision.com |url=https://www.bairdtelevision.com/high-definition-colour-television-19401944.html |access-date=2023-01-23 |website=www.bairdtelevision.com}}{{Cite web |title=The history of colour TV in the UK |url=https://www.scienceandmediamuseum.org.uk/objects-and-stories/history-colour-tv-uk |access-date=2023-01-24 |website=National Science and Media Museum |date=March 17, 2022 |language=en}}

File:Goldmark1940color.jpg

The CBS field-sequential system was an example of a mechanical television system because it relied in part on a disc of color filters rotating at 1440 rpm inside the camera and the receiver, capturing and displaying red, green, and blue television images in sequence. The field rate was increased from 60 to 144 fields per second to overcome the flicker from the separate color images, resulting in 24 complete color frames per second (each of the three colors was scanned twice, double interlacing being standard for all electronic television: 2 scans × 3 colors × 24 frames per second = 144 fields per second), instead of the standard 30 frames/60 fields per second of monochrome. If the 144-field color signal were transmitted with the same detail as a 60-field monochrome signal, 2.4 times the bandwidth would be required. Therefore, to keep the signal within the standard 6-MHz bandwidth of a channel, the image's vertical resolution was reduced from 525 lines to 405. The vertical resolution was 77% of monochrome, and the horizontal resolution was 54% of monochrome.William F. Schreiber, "Introduction to 'Color Television—Part I'", Proceedings of the IEEE, vol. 87, no. 1, January 1999, p. 175.

Because of these variances in resolution and frame rate from the NTSC standards for television broadcasting, field-sequential color broadcasts could not be seen on existing black and white receivers without an adapter (to see them in monochrome), or adapter-converter (to see them in color).[http://www.earlytelevision.org/cbs_color_ads.html#admiral CBS Field Sequential System: Advertisements], Early Television Foundation.

The CBS Sequential Color TV system was first demonstrated to the press on September 4, 1940.

{{Cite news

| author = NYT Staff

| title = Color Television Achieves Realism

| work = New York Times

| date = September 5, 1940

| page = 18

| url = https://nyti.ms/3zVK4Ka

| access-date = 12 October 2024

}} A color 16mm film was telecined to a color TV set and shown to the gathered press in Peter Goldmark's New York CBS lab. Live color from television cameras in a studio was first demonstrated to the press in 1941.

{{Cite news

| author = WSJ Staff

| title = Columbia Broadcasting Exhibits Color Television

| work = Wall Street Journal

| location = New York

| date = January 10, 1941

| page = 4

}} The system was first shown to the general public on January 12, 1950.

{{Cite news

| author = WP Staff

| title = Washington Chosen for First Color Showing From Ages 4 to 90, Audience Amazed

| newspaper = The Washington Post

| date = January 13, 1950

| page = B2

| url = https://www.proquest.com/docview/152302007/

| access-date = October 13, 2024

| url-access = subscription

| via = ProQuest

| id = {{ProQuest | 152302007}}

}}

The Federal Communications Commission adopted the CBS color system as the standard for color television in the United States on October 11, 1950.

{{Cite news

| author = UPI Staff

| title = C.B.S. Color Video Starts Nov. 20

| work = The New York Times

| agency = United Press International

| date = October 12, 1950

| pages = 1, 50

| url = https://nyti.ms/3XX9teu

| access-date = October 11, 2024

}} Public tests started in November 1950. CBS Television began regular, seven-day-a-week color broadcasting on June 25, 1951, in the New York City area, with a one-hour variety show hosted by Arthur Godfrey.

{{Cite news

| author = UPI Staff

| title = First CBS Color TV Broadcast June 25

| work = The Post-Standard

| publisher = The Post-Standard Company

| location = Syracuse, New York

| agency = United Press International

| date = June 13, 1951

| page = 1

| url = https://www.newspapers.com/article/the-post-standard-frist-cbs-color-tv-bro/156947280/

| access-date = October 11, 2024

| via = Newspapers.com

}}

{{Cite news

| author = UPI Staff

| title = CBS Color TV Program Seen By 40,000

| work = Kokomo Tribune

| location = Kokomo, Indiana

| agency = United Press International

| date = June 26, 1951

| page = 13

| url = https://www.newspapers.com/article/the-kokomo-tribune-cbs-color-tv-program/156948414/

| access-date = October 11, 2024

| via = Newspapers.com

}}

In June 1951, Philco offered 11 television models that could show CBS color broadcasts in black and white."Philco Offers 11 TV Sets To Receive CBS Color TV in Black and White", Wall Street Journal, June 4, 1951, p. 9. CBS purchased its own television manufacturer in April 1951 when no other company would produce color sets using the system.

{{Cite news

| author = AP Staff

| title = Hytron's Deal With CBS Seen TV Color Aid

| newspaper = The Washington Post

| agency = The Associated Press

| date = April 12, 1951

| page = 15

| url = https://www.proquest.com/docview/152402459/

| access-date = October 13, 2024

| url-access = subscription

| via = ProQuest

| id = {{ProQuest | 152402459}}

}} Production of CBS-Columbia color receivers began in September and were first offered for retail sale in October."CBS Subsidiary Starts Mass Production of Color Television Sets", Wall Street Journal, September 13, 1951, p. 18. Field-sequential color broadcasts were suspended by CBS on October 20, 1951 after showing the University of North Carolina versus the University of Maryland college football game.

{{Cite news

| author = Times Staff

| title = Color TV Shelved As a Defense Step

| work = New York Times

| date = October 20, 1951

| pages = 1, 28

| url = https://nyti.ms/3Y1Vggu

| access-date = October 12, 2024

}}

The cessation of color broadcasts and selling color TV sets came about mostly by the request of the National Production Authority (NPA), which prohibited the manufacture of color sets for the general public during the Korean War.

{{Cite news

| last1 = Gould

| first1 = Jack

| title = Action of Defense Mobilizer in Postponing Color TV Poses Many Question for the Industry

| work = New York Times

| date = October 22, 1951

| page = 23

| url = https://nyti.ms/3NpTNeM

| access-date = October 12, 2024

}} Allen B. DuMont, owner of the DuMont Television Network, suspected that the reason CBS capitulated so easily was because of the complete lack of public interest in non-compatible color TV, and the NPA being a good excuse to cut costs and end what was a money-losing business.

{{Cite news

| author = Times Staff

| title = Du Mont Challenges Wilson on Color TV

| work = New York Times

| date = October 21, 1951

| page = 47

| url = https://nyti.ms/4eS8Cme

| access-date = October 12, 2024

}}

Only 200 color sets had been manufactured for commercial sale, and only 100 of those had shipped, when CBS suspended its color broadcasts.

{{Cite web

| last1 = Reitan

| first1 = Edwin

| title = CBS Color Television System Chronology

| website = Early Television Museum

| publisher = Early Television Foundation

| location = Columbus, Ohio

| date = November 24, 2006

| url = https://www.earlytelevision.org/Reitan/cbs_chronology_rev_h_edit.html

| access-date = October 11, 2024

| archive-url = https://web.archive.org/web/20120306051133/https://colortelevision.info/Color_Sys_CBS.html

| archive-date = March 6, 2012

| url-status = live

}} CBS announced in March 1953 that it had abandoned any further plans for its color system.

{{Cite news

| last1 = Southwick

| first1 = Paul

| title = CBS Says Confusion Now Bars Color TV

| newspaper = The Washington Post

| agency = United Press International

| date = March 26, 1953

| page = 39

| url = https://www.proquest.com/docview/152566445/

| access-date = October 13, 2024

| url-access = subscription

| via = ProQuest

| id = {{ProQuest | 152566445}}

}}

Meanwhile, RCA continued working on and improving its NTSC compatible color television system, first demonstrated in 1949. By spring 1953, RCA developed an all-electronic color TV system that the NTSC adopted.It remained in service until the adoption of high-definition television in the early 2000's.

{{Cite news

| author = Time Staff

| title = Color Muddle

| work = Time Magazine

| publisher = Time Life

| location = New York

| volume = 61

| issue = 14

| date = April 6, 1953

| page = 65

}} NTSC compatible color superseded the field-sequential system as the color TV standard for the United States when the FCC approved it for public use on December 17, 1953.

{{Cite news

| last1 = Adams

| first1 = Val

| title = F.C.C. Rules Color TV Can Go on Air at Once

| work = New York Times

| date = December 19, 1953

| pages = 1, 23

| url = https://nyti.ms/4dItKdE

| access-date = October 12, 2024

}}

File:368474 apollo11 cameras.jpg

Color broadcast studio television cameras in the 1960s, such as the RCA TK-41, were large, heavy and high in energy consumption. They used three imaging tubes to generate red, green and blue (RGB) video signals which were combined to produce a composite color picture. These cameras required complex optics to keep the tubes aligned. Since temperature variations and vibration would easily put a three-tube system out of alignment, a more robust system was needed for lunar surface operations.{{sfnp|O'Neal|2009b|}}

In the 1940s, CBS Laboratories invented an early color system that utilized a wheel, containing six color filters, rotated in front of a single video camera tube to generate the RGB signal.{{sfnp|Wetmore|1969|pp=18, 20}} Called a field-sequential color system, it used interlaced video, with sequentially alternating color video fields to produce one complete video frame. That meant that the first field would be red, the second blue, and the third field green – matching the color filters on the wheel.{{sfnp|Wetmore|1969|pp=18, 20}} This system was both simpler and more reliable than a standard three-tube color camera, and more power-efficient.{{sfnp|O'Neal|2009b|}}

Stanley Lebar and his Westinghouse team wanted to add color to their camera as early as 1967, and they knew that the CBS system would likely be the best system to study.{{sfnp|Steven-Boniecki|2010|pp=94–103}} The Westinghouse lunar color camera used a modified version of CBS's field-sequential color system.{{sfnp|Wetmore|1969|pp=18, 20}} A color wheel, with six filter segments, was placed behind the lens mount. It rotated at 9.99 revolutions per second, producing a scan rate of 59.94 fields per second, the same as NTSC video. Synchronization between the color wheel and pickup tube's scan rate was provided by a magnet on the wheel, which controlled the sync pulse generator that governed the tube's timing.

The color camera used the same SEC video imaging tube as the monochrome lunar camera flown on Apollo 9. The camera was larger, measuring {{convert|17|in|mm|disp=flip}} long, including the new zoom lens. The zoom lens had a focal length variable from 25 mm to 150 mm, i.e. a zoom ratio of 6:1. At its widest angle, it had a 43-degree field of view, while in its extreme telephoto mode, it had a 7-degree field of view. The aperture ranged from F4 to F44, with a T5 light transmittance rating.{{sfnp|Niemyer, Jr.|1969|p=4}}

Signal processing was needed at the Earth receiving ground stations to compensate for the Doppler effect, caused by the spacecraft moving away from or towards the Earth. The Doppler Effect would distort color, so a system that employed two videotape recorders (VTRs), with a tape-loop delay to compensate for the effect, was developed.{{sfnp|Wetmore|1969|pp=18, 20}} The cleaned signal was then transmitted to Houston in NTSC-compatible black and white.{{refn|group="Note"| The unprocessed signal from the Moon, with its fluctuating TV synchronization signals, was sent to the first VTR and was recorded on 2-inch tape. The tape was not spooled on that machine, but instead, was played back on the second VTR, using the steady house sync signal to play it back and fix any synchronization issues caused by the Doppler effect (this time base correction is now accomplished by digital methods since the mid-1970s).{{sfnp|Wood|2005|p=12}}}}

Unlike the CBS system that required a special mechanical receiver on a TV set to decode the color, the signal was decoded in Houston's Mission Control Center. This video processing occurred in real time. The decoder separately recorded each red, blue and green field onto an analog magnetic disk recorder. Acting as a framebuffer, it then sent the coordinated color information to an encoder to produce a NTSC color video signal and then released to the broadcast pool feed.{{sfnp|O'Neal|2009b|}} Once the color was decoded, scan conversion was not necessary, because the color camera ran at the same 60-fields-per-second video interlace rate as the NTSC standard.{{sfnp|Steven-Boniecki|2010|pp=94–103}}

It was first used on the Apollo 10 mission. The camera used the command module's extra S-band channel and large S-band antenna to accommodate the camera's larger bandwidth. It was only used in the lunar module when it was docked to the command module. Unlike the earlier cameras, it contained a portable video monitor that could be either directly attached to the camera or float separately. Combined with the new zoom lens, it allowed the astronauts to have better precision with their framing.{{sfnp|Wetmore|1969|pp=18, 20}}

Apollo 12 was the first mission to use the color camera on the lunar surface. About 42 minutes into telecasting the first EVA, astronaut Alan Bean inadvertently pointed the camera at the Sun while preparing to mount it on the tripod. The Sun's extreme brightness burned out the video pickup tube, rendering the camera useless. When the camera was returned to Earth, it was shipped to Westinghouse, and they were able to get an image on the section of the tube that wasn't damaged.{{sfnp|Wood|2005|pp=25–28}} Procedures were re-written in order to prevent such damage in the future, including the addition of a lens cap to protect the tube when the camera was repositioned off the MESA.

Image:Apollo 14 golf.jpg" issue with color camera.]]

The color camera successfully covered the lunar operations during the Apollo 14 mission in 1971. Image quality issues appeared due to the camera's automatic gain control (AGC) having problems getting the proper exposure when the astronauts were in high contrast light situations, and caused the white spacesuits to be overexposed or "bloom". The camera did not have a gamma correction circuit. This resulted in the image's mid-tones losing detail.{{sfnp|Wood|2005|pp=31–32}}

After Apollo 14, it was only used in the command module, as the new RCA-built camera replaced it for lunar surface operations. The Westinghouse color camera continued to be used throughout the 1970s on all three Skylab missions and the Apollo–Soyuz Test Project.

The 1969–1970 Emmy Awards for Outstanding Achievement in Technical/Engineering Development were awarded to NASA for the conceptual aspects of the color Apollo television camera and to Westinghouse Electric Corporation for the development of the camera.{{sfnp|Pearson|1969|p=B7}}

For the first nine months of NTSC color in 1953–1954, CBS continued to use its field-sequential color television cameras, with the field rate and signal adapted for NTSC standards, until RCA delivered its first production model of an NTSC color camera in time for the 1954–55 season.{{citation needed|date=October 2020}}

The Soviet Union was the only other country to experiment with a field-sequential color system. It manufactured a small number of color receivers in 1954 that used a mechanical color disc.[http://www.earlytelevision.org/raduga.html 1954 Russian Raduga (Rainbow) Field Sequential Color Set], Early Television Foundation.

Modern day Digital Light Processing (DLP) projectors commonly use color wheels to generate color images, typically running at a multiple of the video frame rate.

{{Cite web

| author = Christie Staff

| title = DLP projector technology

| work = Christie

| publisher = Christie Digital Systems

| location = Cypress, California

| year = 2024

| url = https://www.christiedigital.com/about/display-technology/dlp-projector/#:~:text=Digital%20Light%20Processing%20(DLP%C2%AE,resolution%20of%20the%20projected%20image.

| access-date = October 12, 2024}}

• NTSC Broadcast system that encodes color information into a compatible signal
• SECAM Broadcast system that sends color information sequentially by scan line
• Mechanical television
• Guillermo González Camarena Chromoscopic adapter for television
• History of television
• Penetron – a color CRT system that used field-sequential color

{{reflist|group=Note}}

{{Reflist|30em}}

• {{cite news

| last = Lebar

| first = Stanley

| title = The Color War goes to the Moon

| work = Invention and Technology

| date = Summer 1997

| url = http://www.hq.nasa.gov/alsj/Invent-Tech1997.pdf

| access-date = 2013-10-18

}}

• {{Citation

| last = Niemyer, Jr.

| first = L. L.

| chapter = Apollo Color Camera

| date = 1969-09-16

| editor-last = Jones

| editor-first = Eric M.

| editor2-last = Glover

| editor2-first = Ken

| title = Apollo Lunar Surface Journal

| publisher = NASA

| location = Washington, DC

| publication-date = 1996–2013

| chapter-url = https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790073158_1979073158.pdf

}}

• {{cite news

|last1 = O'Neal

|first1 = James E.

|title = TV's Longest Remote

|work = TV Technology

|url = https://www.tvtechnology.com/news/tv39s-longest-remote

|date = July 6, 2009a

|publisher = NewBay Media

|location = New York

|access-date = October 13, 2024

|archive-url = https://web.archive.org/web/20131019101731/http://www.tvtechnology.com/feature-box/0124/tvs-longest-remote/202657

|archive-date = October 19, 2013

|url-status = live

}}

• {{cite news

|last1 = O'Neal

|first1 = James E.

|title = Equipping Apollo for Color Television

|work = TV Technology

|url = https://www.tvtechnology.com/news/equipping-apollo-for-color-television

|date = July 21, 2009b

|publisher = NewBay Media

|location = New York

|access-date = October 13, 2024

|archive-url = https://web.archive.org/web/20131019101734/http://www.tvtechnology.com/feature-box/0124/equipping-apollo-for-color-television/202793

|archive-date = 19 October 2013

|url-status = live

}}

• {{cite news

| last = Pearson

| first = Howard

| title = Emmy Awards to Top Shows

| url = https://news.google.com/newspapers?id=Yy8xAAAAIBAJ&sjid=ZkkDAAAAIBAJ&pg=6840%2C1831592

| access-date = 2013-10-15

| newspaper = Deseret News

| date = 1969-06-09

| location = Salt Lake City, Utah

| page = B7

}}

• {{cite book

| last = Steven-Boniecki

| first = Dwight

| title = Live TV From the Moon

| year = 2010

| publisher = Apogee Books

| location = Burlington, Ontario

| isbn = 978-1-926592-16-9

| url = http://www.livetvfromthemoon.com/

}}

• {{cite news

|last1 = Von Baldegg

|first1 = Kasia Cieplak-Mayr

|title = 1 Small Step for a Cam: How Astronauts Shot Video of the Moon Landing

|url = https://www.theatlantic.com/video/index/260122/1-small-step-for-a-cam/

|access-date = 2013-10-16

|work = The Atlantic

|date = 2012-07-20

|archive-url = https://web.archive.org/web/20120723123929/http://www.theatlantic.com/video/archive/2012/07/1-small-step-for-a-cam-how-astronauts-shot-video-of-the-moon-landing/260122/

|archive-date = 23 July 2012

|location = Washington, DC

|url-status = live

}}

• {{Citation

|author = Westinghouse

|title = Apollo Color Television Subsystem Operation Manual and Training Manual

|date = 1971-06-01

|publisher = NASA

|location = Houston

|url = http://www.hq.nasa.gov/alsj/WEC-ColorTV-Manual.pdf

|access-date = 2013-10-19

|archive-url = https://web.archive.org/web/20041117090707/http://www.hq.nasa.gov/alsj/WEC-ColorTV-Manual.pdf

|archive-date = 17 November 2004

|url-status = live

}}

• {{cite news

| last1 = Wetmore

| first1 = Warren C.

| title = Docking Transmitted Live in First Color TV From Space

| work = Aviation Week & Space Technology

| date = 1969-05-26

| location = Washington, DC

| pages = 18, 20

}}

• {{cite book

| last = Wilford

| first = John Noble

| title = We Reach the Moon: The New York Times Story of Man's Greatest Adventure

| url = https://archive.org/details/wereachmoonnewyo00wilf

| url-access = registration

| year = 1971

| publisher = Bantam Books

| location = New York

| isbn = 978-0-552-08205-1

}}

• {{cite web

|last1 = Windley

|first1 = Jay

|title = Technology: TV Quality

|work = Moon Base Clavius

|publisher = Clavius.org

|location = Salt Lake City, Utah

|year = 2011

|url = http://www.clavius.org/tvqual.html

|access-date = 2011-12-09

|archive-url = https://web.archive.org/web/20020611221953/http://www.clavius.org/tvqual.html

|archive-date = 11 June 2002

|url-status = live

}}

• {{Citation

| last = Wood

| first = Bill

| chapter = Apollo Television

| year = 2005

| editor-last = Jones

| editor-first = Eric M.

| editor2-last = Glover

| editor2-first = Ken

| title = Apollo Lunar Surface Journal

| publisher = NASA

| location = Washington, DC

| publication-date = 1996–2013

| chapter-url = http://www.hq.nasa.gov/alsj/ApolloTV-Acrobat7.pdf

}}

• [https://web.archive.org/web/20071113101332/http://www.novia.net/~ereitan/ Ed Reitan's Color Television History].
• [http://www.earlytelevision.org/color.html Early Television Foundation: Early Color TV].
• [http://www.hawestv.com/moon_cam/moonctel.htm Comparison of CBS, Col-R-Tel and Apollo moon TV technology].
• [http://www.hawestv.com/mtv_cbssys/cbssysadapt1.htm How experimenters converted NTSC sets to receive CBS System color].
• About.com: [https://archive.today/20120720210830/http://inventors.about.com/library/inventors/blcolortelevision.htm Color Television History].
• John Logie Baird, [http://www.google.com/patents?id=JRVAAAAAEBAJ U.S. patent for color television] {{Webarchive|url=https://web.archive.org/web/20130518084511/http://www.google.com/patents?id=JRVAAAAAEBAJ |date=May 18, 2013 }}, filed 1929.

{{Video formats}}

Category:Television technology