Any Video Security System starts with CCTV security cameras. The images
you see and record can only be as good as the images produced by your CCTV
security cameras. Good security cameras produce good images and vice
versa. There are several critical specification factors which affect the
performance of your cameras and consequently, the quality of your camera
images. These factors also affect the price of cameras. We offer a
selection of CCTV security cameras to meet almost any situational need and
budget. All our cameras provide excellent specification factors, overall
quality and excellent images, coupled with very competitive prices.
Black and White (B/W) cctv security cameras were the most widely used just
a few years ago because of price and better light sensitivity. Today,
color cctv cameras have narrowed the price gap and some of our color cctv
cameras are as light sensitive as B/W cameras. Because color video is much
more lifelike than B/W and provides much more positive identification,
most cctv cameras purchased today are color units.
The main performance factors are:
The Type and Quality of the Imaging Chip in the camera.
CCTV security cameras produce images using CMOS or CCD ( Charge Couple
Device ) chips. Tiny, very low price cctv cameras usually use CMOS
technology, produce poor quality images and have very poor light
sensitivity. Decent quality cctv cameras use CCD technology. The size of
the CCD chip is normally 1/4", 1/3" or 1/2". As a rule of thumb, the
larger the size, the higher the quality of the image produced and the
higher the price. However, higher density 1/4" and 1/3" CCD chips can now
produce as good an image as many 1/3" or 1/2" chips.
The Make of the CCD chip in the camera.
Not all CCD chips are equal, even with the same specifications. Quality
varies by manufacturer. Panasonic and Sony are generally recognized as
producers of the best CCD chips. All CCTV cameras supplied by ADTECH use CCD chips from these two manufacturers.
The Type of DSP (Digital Signal Processing) Chip in the camera.
Digital cctv cameras use a DSP chip to digitize the video stream from the
CCD chip, in order to improve certain picture quality elements and to add
additional functionality. The DSP chip in the camera can have a very large
effect on the quality of the video images produced by the camera. See our
CCTV Color Cameras page for a
more specific explanation of DSP chips.
Number of TV Lines
The number of TV lines in the camera image is a measure of picture
resolution (sharpness). The larger the number of TV lines, the better the
resolution and hence, overall picture quality. Over 380 TV Lines is
generally considered good resolution while over 480 TV lines is considered
high resolution.
Light Sensitivity
Sensitivity ratings are generally given in "lux" (a light level
measurement). The lower the lux number, the lower the light levels at
which the CCTV camera will produce an acceptable image. In other words,
the lower the lux level rating, the more light sensitive the camera. B/W
cameras generally have lower lux level ratings than color cameras ( i.e.
B/W cameras will produce acceptable images in lower light conditions than
color cameras). With the adoption of the new Extra View CCD chips from
Panasonic, we can now offer exceptionally light sensitive color cameras
in our cameras. We are also pleased to offer
several cameras incorporating "frame integration". This method of
electronically boosting light sensitivity by user settable amounts, allows
our "Starlight" cameras to produce a useable color image in as little as
0.003 Lux of light ( the equivalent of the amount of light available on a
starlit but moonless night ).
Signal to Noise (S/N) Ratio
The higher the Signal to Noise ratio, the clearer the video image produced
by the camera. Good cctv cameras will have a S/N ratio of at least 48dB.
Fixed CCTV Cameras come in two main types.
The first type has a camera body, to which lenses of different focal
lengths and/or fixed or variable irises, may be attached. The factors
involved in choosing a suitable lens are given on the
CCTV Camera
Lenses page. Features such as
BLC ( Back Light Compensation), Auto Iris Drive and AES ( Auto Electronic
Shutter) on/off are provided, as is availability in several power inputs
(e.g. 12V DC or 24V AC). New technology cameras now provide an "On Screen
Display" for choosing and setting functions. Because of it's flexibility
of configuration, this type of camera is normally used in most commercial
video surveillance systems.
The second type is basically a fixed lens mounted on a circuit board
(board cameras). These cameras may be packaged in a small case (Mini
Cameras) or dome (Mini Dome) or simply sold unpackaged, for mounting by
the purchaser. Lenses in these cameras are either of a normal industry
aperture or a "pinhole" lens of very small aperture. Pinhole lens cameras
are often called "spy" cameras and may be mounted in a concealed way for
covert surveillance purposes. Since the lenses in board cameras are
pre-mounted, have a fixed iris and are usually of a short focal length
(i.e. wide angle), their flexibility of usefulness is limited. However,
this type of camera can provide a low cost solution in the right
situation, particularly in a home environment.
Pan, Tilt, Zoom Cameras
Once used almost exclusively by large Corporations, Government and
Casinos, Pan, Tilt, Zoom (PTZ) cctv cameras have now become much more
affordable and offer better performance than just a few years ago.
PTZ cameras are able to rotate horizontally through 3600,
vertically through 900 and have electrically powered zoom
lenses capable of giving better than fifteen times optical zoom. Movement
can be very fast and is controlled through a connected controller and/or
through an appropriate DVR.
PTZ cameras are normally mounted in domes and when used outside, the
domes are weatherproof and cooled and heated