Electronic Video Recording (EVR): The Film-Based Video Innovation of the 1960s
Long before the era of digital streaming and DVDs, the quest for efficient video storage led to some fascinating technological experiments. One such innovation was Electronic Video Recording (EVR), a unique film-based video format developed in the 1960s. Designed to bridge the gap between cinema and television, EVR aimed to provide a compact way to store vast amounts of video and documents for household and educational use.
The Origins and Development of EVR
EVR was the brainchild of Peter Carl Goldmark, a Hungarian-born engineer working at CBS Laboratories. Officially announced by CBS on August 27, 1967, the system was engineered to solve the problem of space; it allowed users to archive significant amounts of visual media without the bulk associated with other contemporary formats.
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How EVR Technology Worked
Unlike modern magnetic tapes, EVR utilized a specialized film medium. The system employed a 750-foot length of twin-track 8.75 mm film, which was housed on a 7-inch (180 mm) diameter spool inside a protective plastic cartridge.
Recording and Signal Processing
The recording process utilized electron beam recording to transfer video signals onto the film. The standard configuration consisted of two monochrome tracks moving in the same direction. For color productions, one of the monochrome program tracks was replaced with a dedicated chroma track to handle color information.
Playback via Flying-Spot Scanning
The images stored on EVR film were visible frames, similar to traditional motion picture film. To translate these frames back into a television signal, EVR players used a flying-spot scanner—an optical reading device that scanned the film to convert the stored images into an electronic video signal compatible with television sets.
Commercial Application and BEVR
CBS sought to make EVR a viable consumer product by securing a massive library of content. The company purchased 1,500 classic movies from 20th Century Fox and licensed additional productions from the BBC and Mondadori.
Beyond the home market, CBS introduced a professional version known as BEVR (Broadcast EVR). This version was tailored for television broadcasting and was praised for its extremely high quality, making it a powerful tool for professional studios of the era.
Key Facts
- Developer: Peter Carl Goldmark at CBS Laboratories.
- Announcement Date: August 27, 1967.
- Medium: 8.75 mm twin-track film.
- Storage: 750-foot film on a 7-inch spool in a plastic cartridge.
- Playback Method: Flying-spot scanner.
- Professional Variant: BEVR (Broadcast EVR).
- Content Partners: 20th Century Fox, BBC, and Mondadori.
| Feature | Specification |
|---|---|
| Film Width | 8.75 mm |
| Film Length | 750 feet |
| Spool Diameter | 7 inches (180 mm) |
| Recording Method | Electron beam recording |
| Reading Method | Flying-spot scanner |
Frequently Asked Questions
Who invented Electronic Video Recording?
EVR was developed by Peter Carl Goldmark, a Hungarian-born engineer, while working at CBS Laboratories.
What is the difference between EVR and BEVR?
EVR was intended for household and educational use, while BEVR (Broadcast EVR) was a professional version designed specifically for high-quality television broadcasting.
How did EVR store color images?
While standard EVR used two monochrome tracks, color versions replaced the second monochrome program track with a separate chroma track.
Why is EVR no longer in use?
Despite its high quality, EVR was quickly superseded by the emergence of magnetic tape formats for both professional and consumer markets.
What kind of content was available on EVR?
CBS licensed content from the BBC and Mondadori, and purchased 1,500 old movies from 20th Century Fox to sell on the format.