Video Surveillance Technology Explained - A
Primer
The technology in video surveillance equipment
is used in many ways for the advantage of society as a whole.
The technology is used to investigate, among other things, the
workload amongst pilots and air-traffic controllers, assessment
of driver reactions to warning devices at railroad crossings,
and studies of the performance of sleep-deprived locomotive
engineers, just to name a few. The equipment includes
video
cameras, hidden cameras,
digital video recorders,
digital video cameras, and
CCTV [closed circuit TV] video cameras.
Events such as the 9-11 terrorist attack in the
United States of America and the ever present threat of more
terror attacks has resulted in video surveillance equipment
becoming more popular than any time before.
This equipment and technology is used in various
different portions of society including government agencies,
security agencies, companies and businesses, schools, and public
and private transportation vehicles.
Video surveillance apparatus is also a welcomed
technology in places where around the clock human supervision is
needed but not viable. As an example, the New York City Transit
system [including the subway, tunnel and bridge authorities]
uses video surveillance equipment for monitoring below ground
traffic and stations.
There are many components to video surveillance
equipment technology such as cameras,
software, digital image
cameras, infrared sensors,
monitors and so on.
Surveillance technology has become an invaluable
apparatus for business when it is correctly used. It can lessen
the liability and workers' compensation premiums. It can help
identify fraudulent insurance claims, and may help in the
deterrence and apprehension of dishonest workers and customers.
Present-day technology by the way of computer networks and the
Internet additionally provides the capability to observe a
business concern remotely from home or other locations.
There are many varieties of cameras and digital
video recorders made for a variety of applications. Examples of
these are entrance and exit cameras, cash register and counter
cameras, internal cameras, outdoor cameras, etc. along with
digital video recorders [DVRs] and
[VCRs] are the main
components of a digital video surveillance system.
Prices for the equipment standard for a
four
camera digital video recording system for a small retail or
office type business can cost at least several thousands of
dollars plus the cost of labor of installation. As you might
expect medium, large and project level businesses will need to
spend proportionately more to satisfy their individual security
requirements.
Whatever expenses incurred in buying video
surveillance equipment merits the effort and expense. This is
because this technology not only reduces the cost of security
but also helps in curbing crime and vandalism. There are very
few companies, which do not use video surveillance equipment for
some purpose or the other. Total sales in video surveillance
technology are on the increase. They will continue to do so due
to the effectiveness and versatility of this technology.
Surveillance
Questions
How do hidden cameras work? A small board camera
is built into an everyday item. The camera can be wired which means
it is connected to the DVR or VCR using a cable. The camera can
also be wireless, in this case the camera transmits a signal to
a receiver that is connected to the
DVR or VCR.
Can I get
audio in my
hidden camera? - No you cannot. According to United States federal laws, audio
should not be used in a surreptitious manner. One example of surreptitious
interception is audio in a hidden camera. This includes pinhole
board cameras and all covert or hidden cameras; i.e.,
a clock radio or
a teddy bear.
Audio in a hidden camera or
board camera is only available to law
enforcement agencies. Title 18, Section 2512.
What is the difference between a
wired and
a wireless camera? - Wired cameras have a video cable that
runs from the camera to your recording or viewing device such as
a DVR, VCR or
monitor. Wireless cameras have a built-in transmitter
that sends the video signal to a receiver. The receiver connects
to your recording or viewing device.
How far can a wireless hidden camera transmit? -
Standard wireless hidden cameras can transmit up to 1000 feet
and high-powered wireless hidden cameras can transmit up to 2000
feet.
How many wireless cameras can you have in
one location? - You can have up to
four wireless cameras
in one location. You can view all cameras at once using four receivers
or you can use one receiver and switch to each camera. You will
only be able to view one camera at a time if you only use one receiver.
If you want to install multiple wireless cameras in one location
it's best to order them at the same time so that we can put them
on different channels.
Will a cordless phone interfere with wireless
cameras? - Cordless phone that operate on the 2.4 GHz frequency
will cause interference with 2.4 GHz cameras. Interference should
be minimal and usually occurs if the phone is between the camera
and receiver.
What is a 2.4 GHz wireless frequency? - A
frequency is used to transmit a signal or data like video. 2.4GHz
is the specific wireless frequency that our transmitters use to send
video signal to a receiver. All of our wireless cameras operate
on the 2.4 GHz frequency. Range varies from 200' to 700' depending
on environmental conditions. These units are FCC approved.
Are the transmitters FCC approved? - The transmitters used in all of our wireless systems are FCC and
Industry Canada Certified.
What is CCD? - CCD is used in
professional
cameras because of it's high resolution quality and it's ability
to record in low-light situations. CCD is basically a small silicon
chip that receives light and turns it into voltage variations which
makes up an image. It's usually measured in inches with 1/3"
CCD being the standard. They are higher priced but are great for
cameras that may require vision in near darkness.
What is a Quad? - A
Quad splits your
monitor into 4 sections allowing you to view 4 cameras at once.
Will a Quad allow
four cameras to record at the same time? - Yes you can record all
four cameras at the same time. You also can record using a switching monitor,
which will record the camera that is showing at that moment.
Do the receivers work through walls up to
two feet thick? - Yes as long as there isn't excessive
amount of metal in the wall.
Do the plug and play connections require extra
wire to run the signal back to the VCR or TV? - Yes, you
need to buy the length of cable you need we offer the CA-25,
CA-50 and the CA-100.
What is the difference between a
DVR and a
VCR? - A Digital Video Recorder (DVR) system records high
resolution digital images to a hard disk drive (HDD) and eliminates
the requirement of maintaining VHS tapes. Since the video images
are stored digitally, the image quality will not degrade overtime,
as would a VHS tape when recorded over multiple times. The time-saving
search capabilities of a DVR will enable the user to locate the
desired video clips via user defined parameters (camera, time, date,
etc.) versus the fast forward and rewind functions of a VCR. A DVR
can be accessed remotely from anywhere in the world using the Internet.
How many hours will a DVR record? - The amount of time a
DVR will record for is based on the size
of the DVRs hard drive, the number of cameras recording and the
number of frames per second it is recording at. One camera recording
in Real Time uses 1 GB per day. So a
16 camera system will use 16
GB in one day.
Do I need a VCR from you or can I use my own
VCR? - You can use your own VCR for recording. However,
the VCR will have to be recording all the time. Most VCRs can only
record for about 10 hours but we have
special VCRs that can record
up to 1280 hours.
What is a
DVR card? -
DVR Cards enable
the user to convert their computer into a Digital Video Recorder.
The DVR Card(s) is typically installed in an available PCI slot
of a computer. DVR cards are bundled with
video surveillance software
which allows the user to record and display multiple cameras simultaneously
from the camera site or a remote location.
What is a Plug and Play connection camera? - It is an RCA Video plug and a power plug on the camera
for easy connection to VCR or TV. This is done by running the RCA
(Aux) line into the VIDEO IN of the VCR or TV. The TV or VCR must
be set on the correct channel to view the VIDEO IN picture.
How many cameras can I hook up to one TV? - You can hook up as many cameras as your TV has inputs. Most TVs
have 2 inputs but when using a quad you can hook up four cameras.
Do you need a VCR to record or will the cameras
record? - You must have a
VCR or DVR if you want to record.
How long will the camera last with a 9-volt
battery? - The Cyber Eye and
BD-127 will last 5 hours.
Between what temperatures is it safe for cameras
to operate in?
Safe for B/W cameras to operate between -23°C to + 50°C
or -10ºF to +122ºF
Safe for color cameras to operate between -23º C to
+40ºC or -10ºF to +104ºF
It is safe to store cameras between -30ºC to +70ºC or
-22ºF to +158ºF
What is the operating voltage of a camera? - Our cameras range from 9 volts (CMOS) to 12 volts, and also 24
volt professional models.
What is a varifocal lens? - A varifocal
lens is one where the focal length of the lens can be varied. This
is a fancy way of saying it is a zoom lens. Most varifocal lenses
have, and in almost all circumstances should have, an auto iris
feature.
What is a fixed lens? - A fixed focal
length lens cannot zoom. The focus is fixed. A fixed focal length
lens usually allows more light to pass through the lens at a given
focal length than a varifocal, or zoom lens. This can be important
in low light situations. Looking for something
specific?
Surveillance Definitions
AGC - Automatic Gain Control is an electronic system
found in many types of devices. Its purpose is to control the gain
of a system in order to maintain adequate performance over a range
of input signal levels. Or An electronic circuit that tries to keep
the video signal at a constant level (1 volt peak-peak). Useful on
cameras working at low light levels
AI - Auto Iris is an electronic circuit that acts
as an iris on CCD cameras by electronically shuttering the CCD sensor.
Or An automatic method of varying the size of a lens opening in
response to changes in scene illumination.
AWB - Auto White Balance is an electronic process
used in video cameras to retain true colors. It is performed electronically
on the basis of a white object in the picture.
CCD - Charged Coupled Device: It is analog technology.
The CCD camera has a little bit higher resolution than CMOS. The
camera also functions better in low light. A CCD camera drains a
little bit more power than the CMOS cameras. It uses 12v instead
of 9v. CMOS camera is smaller than a CCD camera and works longer
with the 9v battery.
HAD CCD - Hole Accumulation Diode is a type of
CCD sensor with a layer designed to accumulate holes (in the electronic
sense), thus reducing noise level.
S to N Ratio - Signal to Noise Ratio is simply
the ratio of the signal power and noise power, expressed in decibels
(dB). Or measure of noise on a video signal. It is represented in
Decibels as the level of the video signal compared to the level
of noise present on that signal. The higher the signal to noise
ratio the better.
BLC - Balance Light Control is a method to compensate
for bright spots in a picture. It is also important to consider
whether there are bright spots in the picture such as car headlights
which can make identification of the vehicle registration or model
impossible. This can also be a major problem where it is necessary
to identify a person who is moving from bright daylight into artificial
light. This could result in the subject becoming an unidentifiable
silhouette.
OSD - On Screen Display is a method of displaying
set-up information or instructions on to a
display monitor.
Resolution - Resolution measures the cameras ability
to reproduce an image. The higher the resolution, the better the
picture quality.
LUX - LUX is the measurement of low light needed
for the camera to view and record properly.
FPS - Frames Per Second is the number of still
frames (pictures) that give the illusion of motion, which appear
in a single second of time.30fps is considered "Real Time".
So for Real Time viewing of your cameras, you need at least 30fps
for each camera.
IR - Infrared, IR LEDS are used on Day/Night cameras
which allow the camera to see in the dark.
Focal Length - the distance from the surface of
a lens and its focal point.
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