Video Camera and CCTV Terminology
Common CCTV Terminology
Image Device
This is the type of sensor used to pick up light and convert it into a signal
that can be recorded or seen remotely. This is the most important part of
the camera and determines how good the picture is, how well it does in low
light or no light conditions, and how it adjust to changes and variations
in lighting conditions among other things. Common types that we carry are
listed below.
CMOS
Sony ExMor
Sony Super HAD CCD
Sony Super HAD CCD II (Effio-E and Effio-P)
Sony ExView HAD CCD
Sony ExView HAD CCD II (Effio-E and Effio-P)
PixelPlus CMOS
Current
Measured in milliamps, this is the minium amount the camera needs in order
to function properly. This information is usually located on the power
supply.
Power or Voltage
Measure in voltage, this number needs to be exact and matching on
the camera and the power supply. Common voltages are 12v DC and 24v AC.
Please note that some cameras offer dual voltage usually allowing either
12v DC or 24v AC to be used. 24v AC is normally used for longer runs as
it carries further than 12v DC.
Effective Pixels, Video Resolution
Measured in Height x Width in a unit called Pixels, this measure how
many "Pixels" or squares that will make up your image. The higher
the number the better the image quality. For a total numbers of pixels
multiply the numbers. A 640x480 image has 307,000 pixels, where a 2mp
or 1920 x 1080 display has 2,073,600 pixels.
Operating Temp.
Recommended tempture for the environment the camera will be working in.
If the environment is going to exceed these standards consider some of
our outdoor cameras that have a built-in Heater and blower.
Sensitivity, Lux Rating
Lux is used to measure how much light is needed for an image to be picked
up by the camera. 1 Lux is equal to a candle at 1 meter (or about 3 feet)
away.
S/N Ratio
Signal to Noise Ratio is how much noise or interference in the line
the camera can get and still have a picture. This is measured in decibels
and is affected by the power, length of the wire run to the camera and
sometimes the type of camera. The higher the number the more interference
and the lower the picture quality, once it goes past the rating the picture
will normall go out.
Lenses - Types
Pinhole - Cone shaped, normally used for covert applications.
Board - Flat lens most commonly used.
Varifocal - Adjustable, normally manually, lens. These lenses allow a
range of sizes and levels and allows for precise placement and size of
the picture.
Lenses - Sizes
Lenses come in a variety of sizes, they determine the FOV (Field of View)
and the zoom level of the camera.
Video Connections
There are a few different types and ways of hooking up a camera to a given
DVR or other video systems
BNC - Standard for CCTV systems, this connection has a unique twist and
lock mechanism that keeps the cables from getting pulled apart. BNC stands
for British Naval Connector.
RCA - Standard connection used on most TVs, this connector just pushes
in (normally yellow in color) and is not frequently used for CCTV systems.
Generally also used for audio connections.
Wireless
Wireless video is sent without a wire much like cell phones and
wireless phones send audio. This type of setup does not require or use
an internet connection. These systems will still require a power line
unless an optional battery is used.
WiFi
WiFi is a different type of wireless connection that acts more
like your laptop or desktop computers. This type of setup does require
a Wifi connection and if internet is available you will be able to remotely
view these cameras. This system also requires a power connection running
to it, and generally does no perform well with batteries.