Feb 16, 2009

Video Camera History

A capsule history of video cameras, that focuses on their operation, I also posted to wikipedia. http://en.wikipedia.org/wiki/Professional_video_camera#History

Professional television camera history has two main lines: the gradual shrinking of the camera as it became more versatile and self contained; and a progression of sensors from large insensitive tubes to smaller, much more sensitive tubes and finally to very small, very sensitive solid state chip imagers. Cameras that contained their own recording mechanisms did not appear until the early 1980s.

Early studio television camera -- Gray box on right is the lens, gray box on top is the Viewfinder, sides are lowered to show internal electronics.

At the beginning, these cameras were very large devices, almost always in two sections. The camera section held the lens and tube pre-amps and other necessary electronics, and was connected with a large diameter multi-core cable to the rest of the camera electronics, usually mounted in a rack. The rack would be in a separate room in the studio, or in a remote truck. The camera head alone could not generate a video picture signal on its own. The video signal was output from the rack unit to the rest of the studio for switching and transmission. By the fifties, electronic miniaturization had progressed to the point where some monochrome cameras could operate stand alone and even be handheld. But the studio configuration remained, with the large cable bundle transmitting the signals back to the CCU (Camera Control Unit). The CCU in turn was used to align and operate the camera's functions, such as exposure, system timing, and video and black levels.

The first color cameras (1950s in America, early sixties in Europe), notably the RCA TK-40/41 series, were much more complex with their three (and in some models even four) pickup tubes, and the size and weight drastically increased. Handheld color cameras did not come into general use until the early 1970s, and the first ones were two pieces, a camera head shoulder unit that held the lens and tube section, and a backpack unit. The Ikegami HL-33 was the first of this type, but was followed a up by one piece cameras. These one piece cameras, (The HL-77 from Ikegami and the TK76 from RCA) made possible, in combination with portable 3/4" U-matic VCRs, the introduction of Electronic News Gathering (ENG), which very rapidly replaced the 16mm film cameras that had been the dominant method for capturing news events. This established the standard operation in the field of a two person news crew, one operating the camera, and one carrying the shoulder strapped U-matic recorder and a boom microphone. The control layout for the camera's most important functions was also established with these cameras, and continues to define an ENG camera to this day.

In the early 80s, the first cameras with on board cameras were brought to the market. The far more successful of these used the Betacam recording system. At first these cameras used pickup tubes, and the recorders were of the removable type. Models with CCD imagers came on the scene in the mid-80s. These brought multiple benefits. They were much more stable and less prone to drift than tube cameras, and didn't require a warm up or calibration time at the beginning of the day. They also were not prone to image burn in or streaking caused by bright lights. The early models did not have the resolution or color quality of their tube counterparts, but successive models quickly pulled ahead of tube technology. Eventually, cameras with the recorder permanently mated to the camera head became the norm for ENG.

Studio camera technology did not stand still during this period. The camera electronics shrunk, and CCD imagers replaced the pickup tubes. The thick multi-core cables connecting the camera head to the CCU were replaced in the late seventies with triax connections, a slender video cable that carried multiple video signals, intercom audio, and control circuits, and could be run for a mile or more. As the camera innards shrunk, the electronics no longer dictated the size of the enclosure. But the box shape remained, as it was necessary to hold the large studio lenses, teleprompters, studio viewfinder, and other paraphernalia needed for studio and sports production. Electronic Field Production cameras were often mounted in studio configurations inside a mounting cage. This cage supported the additional studio accessories.

In the late 90s, as HDTV broadcasting commenced, HDTV cameras suitable for news and general purpose work were introduced. Though they delivered much better image quality, their overall operation was identical to their standard def predecessors. New methods of recording for ENG cameras were introduced to supplant tape. Ikegami and Avid introduced EditCam in 1996, based on interchangeable hard drives. Panasonic introduced P2 cameras. These recorded a DVCPro signal on interchangeable flash card media. Several other databased recording systems were introduced, notably XDCam from Sony, and as of 2009, it remains to be seen what will become the predominant method of camera media for professional use in the 2010s.

ENG Video Camera Definition

What's the difference between the big shoulder cameras pros use, and small handheld camcorders? Here's a piece I edited on Wikipedia that I liked so much, I thought I'd reprint it here.

Though by definition, ENG (Electronic News Gathering) video cameras were originally designed for use by news camera operators, these have become the dominant style of professional video camera for most uses, from shooting dramas to documentaries, from music videos to corporate training. While they have some similarities to the smaller consumer camcorder, the following differences should be noted:

* ENG cameras are larger and heavier, and usually supported by a shoulder stock on the cameraman's shoulder, taking the weight off of the hand, which is freed to operate the lens zoom control. The weight of the cameras also helps dampen small movements.
* 3 CCDs are used instead of one, one for each primary color
* They have interchangeable lenses.
* All settings, white balance, focus, and iris can be manually adjusted, and automatics can be completely disabled.
* The lens is focused manually and directly, without intermediate servo controls. However the lens zoom and focus can be operated with remote controls in a studio configuration.
* Professional connectors - BNC for video and XLR for audio. There are at least two XLR audio inputs.
* A complete timecode section is available, allowing time code presets; and multiple cameras can be timecode-synchronized with a cable.
* "Bars and tone" will be available in-camera (the color bars are SMPTE (Society of Motion Picture and Television Engineers) Bars, a reference signal that simplifies calibration of monitors and setting levels when duplicating and transmitting the picture.
* Recording is to a professional medium like some variant of Betacam or DVCPRO or Direct to disk recording or flash memory. If as in the latter two, it's a data recording, much higher data rates (or less compression) are used than in consumer devices.
* The camera is mounted on tripods and other supports with a quick release plate.
* A rotating behind the lens filter wheel, for selecting an 85A and neutral density filters.
* Controls that need quick access are on hard physical switches, not in menu selections.
* Gain Select, White/Black balance, color bar select, and record start controls are all in the same general place on the camera, irregardless of the camera manufacturer.
* Audio is adjusted manually, with easily accessed physical knobs.