Marvin Camras
Marvin Camras was an influential American inventor and electrical engineer, born on January 1, 1916, in Chicago, Illinois. He exhibited a passion for technology from a young age, creating devices such as a flashlight and a telephone to communicate with family. Camras's pivotal contributions began during his time at the Armour Institute of Technology, where he developed a wire recorder that significantly advanced the field of sound recording. His innovations continued during World War II, where his wire recorders were utilized by the military for various training and intelligence purposes.
After the war, Camras shifted his focus to magnetic tape recording, developing key technologies that are foundational to modern audio and video media, including the ferric oxide coating for tape and high-frequency bias recording. Over his career, he secured more than five hundred patents and played a significant role in the evolution of recording technologies, influencing industries such as music and film. Despite his groundbreaking work, Camras remained a private individual, dedicating much of his life to teaching at the Illinois Institute of Technology and nurturing his family. He passed away on June 23, 1995, and is remembered for his substantial impact on sound recording and technology.
Marvin Camras
American electrical engineer
- Born: January 1, 1916
- Birthplace: Chicago, Illinois
- Died: June 23, 1995
- Place of death: Evanston, Illinois
Camras invented a magnetic tape recording process widely used in electronic media, including music and motion-picture sound recording, audio and videocassettes, floppy disks, and credit card magnetic strips.
Primary field: Electronics and electrical engineering
Primary invention: Magnetic tape recording
Early Life
Marvin Camras was born in Chicago, Illinois, on New Year’s Day, 1916. From early childhood, he was fascinated by technology. At the age of four, he built a flashlight, and he later designed a working telephone so he could talk with his cousin William. After high school, Camras attended the Armour Institute of Technology (now the Illinois Institute of Technology, or IIT), where he studied electrical engineering. At that time, his cousin was hoping for a career in opera.
Camras searched for a way to record his cousin’s voice. Drawing upon the work of Danish inventor Valdemar Poulsen (1869-1942), whose telegraphone was an early device for recording sounds magnetically, Camras tried using magnetized piano wire to record his cousin’s singing. In early attempts, the wire twisted during playback, distorting the sound. Camras kept working on his invention and eventually found a solution. He designed a magnetic recording head that would surround the wire but not actually touch it. The results were impressive, at least in terms of recording quality. When Camras demonstrated the wire recorder for his professors at the Armour Institute of Technology, they were so impressed with the clarity of the sound reproduction that they offered Camras a position at the Armour Research Foundation. William, apparently, was less impressed: After hearing the playback of his voice, he gave up his plans for a singing career.
Life’s Work
Marvin Camras received his bachelor of science degree from the Armour Institute of Technology in 1940, during the final years of the Great Depression. Unlike many new graduates of that time, he was fortunate to have a job waiting for him upon graduation. Camras’s professors encouraged him to keep working on his wire recording techniques at the Armour Research Foundation, which in 1940 merged with the Lewis Institute to become the Illinois Institute of Technology, while earning his master’s degree. Camras completed his M.S. in 1942.
In December, 1941, Camras submitted his first patent for a “Method and Means of Magnetic Recording.” It was approved in 1944. By this time, the United States had entered World War II, and Camras’s work attracted the attention of the military. An article published in Time magazine in 1943 discussed the potential wartime benefits of Camras’s “highly portable little gadget,” a wire recorder approximately the size of a typewriter and weighing ten pounds. Far less bulky than earlier recording devices, the magnetic wire sound recorder Camras developed was seen as a way for newscasters to record live broadcasts from the scene of battle. The article noted that Camras, described as a “stocky, shy 27-year-old,” would receive a 25 percent royalty for each recorder sold.
During World War II, Camras’s wire recorders were used by the armed forces for training and intelligence purposes. The Navy used his recorder during submarine pilot training to simulate depth-charge attacks. The Army also used Camras’s “Model 50” recorder for a special military disinformation program kept secret until after the war. To divert the attention of enemy forces, battle sounds were recorded and amplified, then played in locations where the D-Day invasion was not going to take place.
After the war, Camras continued working on recording techniques but switched his medium from wire to a thin, flexible yet durable tape. After experimenting with many different methods to magnetize the tape, he developed a ferric oxide “paint.” This coating, whose particles would align uniformly when magnetized, created an ideal recording surface. This innovation proved to be an enormous commercial success, making “tapes” of one sort or another (audio, video, even computer) a nearly ubiquitous household item. In his Magnetic Recording Handbook (1988), Camras describes the introduction of a home tape recorder in 1946; as postwar prosperity increased the market for consumer goods, such products and their accessories became a multimillion-dollar industry.
Continuing to innovate, in 1949 Camras invented high-frequency bias recording, a method of using high-frequency sounds to sensitize magnetic tapes, allowing for a clear, almost distortion-free reproduction of sound. Camras describes the complex process in depth in his Magnetic Recording Handbook. Some of his other inventions included patents in methods of stereo tape recording, multitrack recording, motion-picture sound-track recording, and an early prototype (1950) of a videotape recorder. In all, Camras patented more than five hundred inventions, largely in the field of electronics. Among the corporations that licensed his patents were General Electric, Minnesota Mining and Manufacturing (3M), and Eastman Kodak.
Despite his many successful inventions, Camras never attained great wealth. Yet he clearly loved his chosen field. His work with the IIT Research Institute continued through 1987, and he continued to teach electrical engineering at the Illinois Institute of Technology until 1994, when he was well into his seventies. Camras was awarded an honorary doctorate from IIT in 1968. He was inducted into the National Inventors Hall of Fame in 1985 and was also awarded the prestigious National Medal of Technology from President George H. W. Bush in 1990.
Camras lived for most of his adult life in Glencoe, Illinois. In his private life, the pioneer of sound recording techniques enjoyed playing the harmonica and making violins and violas. Some of the instruments he designed were used by his daughter, Ruth Camras Prickler, a musician and music teacher, and son-in-law, Charles Prickler, head of the Chicago Symphony Orchestra. Marvin Camras died of kidney failure on June 23, 1995. He was survived by his wife of many years, Isabelle Pollak Camras, four sons, a daughter, and six grandchildren. In an obituary published in The New York Times, Ray Dolby, the chairman of Dolby Laboratories, Inc., maker of professional sound equipment, praised Camras’s contributions to the field of sound recording, calling him “a legend” whose basic designs and discoveries are still used in tapes and recorders.
Impact
Camras invented the magnetic tape recording method that became the basis of most electronic media, including audio and videocassettes, computer floppy disks, and credit card magnetic strips. His design of a magnetic tape head, used first in wire recorders and later in tape recorders, greatly simplified the recording and playback process and improved sound quality. His later work in high-frequency bias recording, multitrack recording, and related technologies further refined the clarity of sound reproduction. Camras’s simple invention, born out of a desire to record a relative’s singing, became a fundamental part of the multibillion-dollar music, film, and computer industries. Yet Camras himself shunned the spotlight, living a life marked by stability and continuity, working, teaching, and raising a family in the same midwestern community where he lived for most of his life.
Camras spent an impressive fifty-year career at the Armour Research Foundation and the Illinois Institute of Technology, where he taught from the 1940’s until 1994. During those years, he earned more than five hundred U.S. and international patents for his work. His professional honors included the National Inventors Hall of Fame, the National Medal of Technology, and fellowships in the Institute of Electrical and Electronics Engineers (IEEE) and American Association for the Advancement of Science (AAAS).
Bibliography
Camras, Marvin. Magnetic Recording Handbook. New York: Van Nostrand Reinhold, 1988. Profusely illustrated with photographs and diagrams, this is a scholarly study of the history, theory, and technology of magnetic recording. Camras describes recording techniques and media, covering his own contribution as well as those of scientists who preceded and followed him. Illustrations, bibliography, index.
‗‗‗‗‗‗‗, ed. Magnetic Tape Recording. New York: Van Nostrand Reinhold, 1985. Anthology of scholarly articles on the technology of sound recording. Includes Camras’s original 1941 patent application. Illustrations, citation index, subject index.
Gilpin, Kenneth N. “Marvin Camras, 79, Inventor in Tape Recording.” The New York Times, June 28, 1995, p. B8. Obituary article provides a summary of Camras’s life and scientific contributions.
McGrath, Kimberley A., and Bridget Travers, eds. World of Invention. Detroit, Mich.: Gale Research, 2001. 2d ed. Includes a short biographical sketch of Camras’s life and a summary of his innovations in the field of magnetic recording. Bibliography, index.
Morton, David. Off the Record: The Technology and Culture of Sound Recording in America. New Brunswick, N.J.: Rutgers University Press, 2000. Lively, well-documented study of the history of recording in the United States, covering both technological and cultural aspects of sound recording. Illustrations, bibliography, index.
Raichel, Daniel R. The Science and Applications of Acoustics. New York: Springer Science & Business Media, 2006. A scholarly study of the fundamentals of acoustics. Chapter 19, “Sound Reproduction,” is of particular interest, placing Camras’s contribution in the context of other recording techniques.
“Wire for Sound.” Time, May 17, 1943. Contemporary news article about Camras’s work for the military discusses possible wartime uses for his magnetic recording device.