Any
Video Security System starts with CCTV surveillance
cameras. The images you see and record can only
be as good as the images produced by your CCTV
surveillance cameras. Good surveillance cameras
produce good images and vice versa. There are
several critical specification factors which
affect the performance of your surveillance
cameras and consequently, the quality of your
camera images. These factors also affect the
price of security cameras. We offer a selection
of CCTV security cameras to meet almost any
situational need and budget. All our surveillance
cameras provide excellent specification factors,
overall quality and excellent images, coupled
with very competitive prices.
Black
and White (B/W) CCTV surveillance cameras were
the most widely used just a few years ago because
of price and better light sensitivity. Today,
color cctv security cameras have narrowed the
price gap and some of our color CCTV surveillance
cameras are as light sensitive as B/W surveillance
cameras. Because color video is much more lifelike
than B/W and provides much more positive identification,
most CCTV surveillance cameras purchased today
are color units.
The
main performance factors are:
The
Type and Quality of the Imaging Chip in the
camera
CCTV
surveillance 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 Professional Security
Group use CCD chips from these two manufacturers.
The
Type of DSP (Digital Signal Processing) Chip in
the camera
Digital
CCTV security 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 400 TV
Lines is generally considered good resolution
while over 500 TV lines is considered high resolution.
All our CCTV cameras have a resolution of
well over 400 TV Lines.
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 "X"
series of Mintron CCTV 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.
Our Mintron™ color cameras have an actual S/N ratio
of 60dB - much better than most.
Fixed
CCTV surveillance 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
surveillance 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.
Our
CCTV surveillance camera product line includes:
