John Logie Baird recorded television in 1927 that nobody could watch for decades
In 1927 John Logie Baird captured television pictures on discs he called Phonovision, the first somewhat successful attempt to record video at all. No machine of the day could play them back. Only in the 1980s did new techniques finally recover the images, letting people see footage that had been stored and silent for more than half a century.
The first video cameras were mechanical. Experimental broadcasts from the 1910s to the 1930s used a spinning perforated Nipkow disk to break a scene into lines. By the 1930s fully electronic camera tubes had replaced it, notably Vladimir Zworykin's Iconoscope and Philo Farnsworth's image dissector. Tubes dominated until the 1980s despite nagging faults such as burn-in and streaking.
Solid-state chips ended the tube era. They grew from the MOSFET transistor invented at Bell Labs in 1959, and Bell Labs also produced the first semiconductor image sensor, the charge-coupled device, in 1969. Olympus devised an active-pixel sensor in 1985, and NASA's Jet Propulsion Laboratory developed the CMOS version in 1993, the kind now found in phones. Because these sensors output digital data directly, they made an all-digital workflow practical. Raw digital video, however, needs enormous storage, so compression mattered just as much, above all the discrete cosine transform proposed in 1972, which underpins the MPEG and H.26x standards introduced from 1988.
Recording caught up in stages. Tape experiments began in 1951, and Ampex sold the first commercial system, Quadruplex, in 1956, adding colour two years later. Sony's DV-2400 Portapak of 1967 let crews record outside the studio, and Betacam in 1981 put the recorder inside the camera, creating the camcorder. Tape later gave way to optical discs, hard drives and flash memory.
Cameras have since spread everywhere. Studio models usually carry three sensors, one each for red, green and blue. Security cameras pan, tilt and zoom without anyone present, and some industrial units are hardened against radiation or intense heat. Others see infrared for night vision, and many phones now shoot 4K.
Source: Video camera
