All video cameras contain 3 major components – the

lens, imager, and recorder. The lens gathers and

focuses the light on the imager, which is normally

a charge coupled device (CCD) or CMOS sensor IC.

Finally, the recorder will encode the video signal

into a form that can be stored. Commonly, the optics

and imager are known as the camera section.

The optic lens is the first component in the camera

section’s light path. The optics normally have one

or more the following adjustments:

1. aperture – controls the amount of light

2. zoom – controls the field of view

3. shutter speed – captures continuous motion

In most consumer units, these adjustments are

automatically controlled by the video camera’s

electronics, normally to maintain constant exposure

onto the imager.

The imager is the “eye” of the camera, housing a

photo sensitive device or devices. The imager works

to convert light into an electronic video signal

through an elaborate electronic process. The

camera lens projects an image to the imager surface,

exposing the photo sensitive array to the light.

The light exposure is then converted into an electrical

charge. Towards the end of the timed exposure, the

imager will convert the accumulated charge into a

continuous analog voltage at the imager’s output


The third piece, the recorder, is responsible for

writing the video signal to a recording medium,

such as magnetic videotape. The recording function

involves many steps of signal processing, and

historically, the recording process introduced

some distortion and noise to the stored video,

such that the playback of stored signal may not

retain the same detail as the original live feed.

All but the most primitive of video cameras will

also need to have a recorder controlling section

which will allow you to control the camera. You

can also swich the recorder into playback mode

for reviewing your recorded footage.

The image you recorded doesn’t need to be limited

to what appeared in the view finder. For a

documentation of events such as those used by the

police, the fields of view will overlay such

things as the time and date of the recording along

the top and bottom of the image.

As you can probably tell now, a high definition

video camera is very complex indeed. There are

several other parts involved as well, although the

above are the most important. A HD video camera

is very complex in build, making it something

that is more than worth the time it takes to create.

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