The Television CameraThe television camera is still the most important piece of production equipment. In fact, you can produce and show an impressive short video piece solely with a camcorder that is small enough to fit in your shirt pocket. Almost all other productions equipment and techniques revolve around the camera or are greatly influenced by its technical and performance characteristics.

Parts of the camera

LensImaging Device

Viewfinder

AmplifierProcessor

Beam Splitter along with Change-coupled devices (CCDs)

Object

From light to video signal

• The light reflected off the object is gathered by the lens and focused on the beam splitter, which splits the white light of the image into red, green, and blue pictures. These beams are directed toward their respective sensors (CCD or CMOS), which transform the RGB light into electric RGB charges; these are amplified, processed, and then reconverted by the viewfinder into video pictures.

Imaging device

The principal electronic component that converts light into electricity is called the imaging device. (also called pickup device and sensor). In Tech lingo it is known as the chip. There are two types of sensors in use; a charge-coupled device (CCD) and a CMOS (complementary metal-oxide semiconductor). Although technically different, they look alike and perform the same function. Both convert the optical image into electrical impulses.

Both CCD and CMOS contain hundreds of thousands or, for high-quality chip millions of image sensing elements called pixels that are arranged in horizontal and vertical rows. Each pixel is a discrete image element that transforms its color and brightness information into a specific electric charge.

Beam splitterIn a typical three-chip design, light that enters

the camera housing is first split into three beams and then focused onto three CCD arrays, each of which has a color filter laminated to the light sensitive side of the array. This method has been very popular, because the spectral response function characteristics of the color filters can be designed to simulate those of the human eye, thus enabling the camera to behave like the color vision model presented earlier. The benefits of this design include simple signal processing, very accurate color reproduction and control, and high resolution.

Striped and Mosaic Filters

Cameras with only one image sensor use a striped or mosaic-like filter instead of a prism block to divide the white light into RGB color beams. Each colored beam is then transduced by the single sensor into electric charges that eventually become the RGB signals.

Mosaic RGB Filter

Striped RGB Filter

Standard Studio Camera Chain

Sync generator

CCU

Power Supply

Camera Head

The Sync Generator

The sync generator produces electronic synchronization pulses – sync pulses – that keep in step the scanning of the various pieces of equipment (cameras, monitors, and video recorders). A genlock provides a general synchronization pulse called house sync. Through the genlock process, the scanning of video signals of a variety of equipment is perfectly synchronized, allowing you to switch among and intermix the video signals of various cameras and/or video recorders without the need for additional video equipment.

Types of cameras

Studio camera on studio PedestalEFP/ENG Camera

Electronic featuresImaging device – most high quality cameras and camcorders have three CCDs or CMOS sensors as the imaging device

Scanning – When shooting HDTV or HDV, you should be able to switch among the 480p, 720p, and 1080i scanning systems; 720p and 1080i are considered true high definition.

Aspect ratio and essential area – all HDTV and HDV viewfinders have an aspect ratio of 16 X 9, which means they are 16 units wide by 9 unit high. Most cameras allow you to switch between 16 X 9, and 4 X 3 areas.

Gain – when there is not enough light for the imaging device to produce optimal video, the gain control comes to the rescue. It is an electronic charge that tricks the sensors into believing that they are getting more light than they actually receive from the lens.

Electronic shutter – The electronic shutter in a television camera functions just like the mechanical one in an old still camera that uses actual film. The shutter can go from 1/8 second to 1/10,000 second.

White balance – Adjusting the RGB signals in such a way that the white object looks white on-screen regardless of whether it is illuminated by reddish or bluish light.

Color BasicsHue – describes the color itself, such as red ball, a green apple, or a blue coat.

Saturation – indicates the richness or strength of a color.

Brightness – (also called lightness or luminance) is how dark or light a color appears on a black-and-white monitor or, roughly how dark or light a color appears.

Waveform monitorWhite level 100

Black level 7.5Zero level

The waveform monitor show a graph of the luminance (black-and-white) portion of the video signal. It also shows the white level(the upper limit of the signal) and the black level (the lower limit of the signal).

Color mixing

When mixing colored light, the additive primaries are red, green, and blue (RGB). All other colors can be achieved by mixing certain quantities of red, green, and blue light. For example the additive mixture of red and green light produce yellow.