||Audio / Video
See: Power Supply - All CCTV devices require power of some sort. Electricity in the United States comes in one form, 110 to 120 AC. The AC adaptor converts the AC power to DC power and will adjust it to a specified amperage. Power supplies should come included with each item.
||Auto electronic shutter - the
ability of the camera to compensate for
moderate light changes in indoor
applications without the use of auto
||A connection from an alarm or sensor that triggers the CCTV unit to start recording if activated.
||Two main methods exist for representing data in electronics -- Analog, and Digital. Analog is pertaining to a mechanism that represents data by measurement of a continous physical variable, as voltage of pressure.
Analog cameras are used most often in CCTV applications. Other examples of of Analog devices are security VCRs, switchers, multiplexors, and quads. CCTV systems that consist of Analog devices are considered Analog Systems.
|Angle of View
Regarding CCTV security cameras, this term refers to the angular range in degrees that you can focus the camera without distorting the image. When focus is distant, the
Angle of View is smaller or narrower. When focusing up close, you can generally see a wide Angle of View.
||The Aperture is the opening of a lens that controls the amount of light let into the camera. The size of the Aperture is controlled by the iris adjustment. By increasing the stop number less light is permitted to pass into the camera.
|Armor Dome Camera
Armor Dome refers to a hi-impact reinforced polycarbonate dome casing designed to resist vandalism on this brand of camera.
|Auto Electronic Shutter
||A CCTV camera feature that allows the camera to compensate for moderate light changes in indoor applications without the use of Auto Iris Lenses.
|Auto Iris Control
||A lens which allows the Aperture to automatically open or close to maintain proper light levels on the faceplate of the camera pickup device.
|Auto Gain Control
||An electronic circuit used by which
the gain of a signal is automatically
adjusted as a function of its input or
other specified parameter.
|Auto White Balance
||A feature on color cameras that
constantly monitors the light and
adjusts its color to maintain white
||Audio Video Interleave - An
audio-video standard designed by
||Backlight Compensation - The ability of a camera to compensate in cases where a subject with a large amount of background light would otherwise be obscured by blooming or silhouetting.
A type of camera with a bullet like
shape. Can be used inside or out. Some
come with infrared lighting.
|| C-Mount or Standard Body cameras are designed to
accommodate custom lenses. The lenses
can be removed and replaced. Standard
Body Cameras are the basic model and
offer the most diverse range of
||Category 5 (cable) - type of cable most often used in networking applications.
||Charge-Coupled Device - CCTV security cameras produce images using CMOS or CCD chips. CCD chips are higher quality and produce a better image than CMOS. Also known as a Color-Capture Device.
||Complementary metal-oxide-semiconductor -A major class of integrated circuit technology used for a wide variety of analog circuits such as image sensors, data conveters, and highly integrated transceivers for many types of communication.
||The wiring used to connect
electronic devices. Cables transmit
different kinds of signals such as
video, power, data, and audio signals.
Refer to plug and play cable and RG59
Siamese cable for more information.
||Compression is the act of taking an incoming signal or image, which can be analog or digital, and restructuring the data such that it takes less resources for storage and transmission.
||A covert application refers to a
situation where you don't want the
person to know that they are being
watched or recorded. Also known as
Day / Night Camera
Not to be confused with Infrared Cameras, "Day/Night Cameras" are regular cameras with a highly sensitive CCD chip with the ability to capture quality imagery with very little light present.
||Two main methods exist for representing data in electronics, Analog and Digital. Digital information is communicated by designating a circuit on or off.
Digital CCTV security camera systems are only lately gaining popularity. Most security cameras are still analog, though DVRs are becoming the industry standard. There are some digital cameras available but they are extremely expensive. Most new systems installed today will include analog security cameras and a DVR. Any CCTV security camera system that includes a DVR is considered a Digital Sytem.
A type of camera with a dome-like shape. Most often used indoors. Some feature infrared lightning and some are designed to be tamper-proof, such as the Armor Dome Camera.
||Dynamic Name Service is
simply a database of IP addresses and
Domain Names. This database is
responsible for telling the internet how
to route a request based only on a name
and not an IP address. GeoVision
supports the use of dynamic IP's for
it's DVR servers and through their
Dynamic DNS service you can always find
your server based only on it's domain
||A duplex grants the ability to transfer data in and out of the recorder at the same time. In example, a full duplex DVR can continue capturing and recording images even while a different image is being displayed.
Digital Video Recorder - A Digital Video Recorder, when applying to an CCTV security camera application, is a computer that coverts the incoming (analog) signal from cameras to digital, and compresses and stores the data. The DVR replaces the function of a multiplexor and a security VCR.
|Field Of View
||The visible area of a
lens. With security cameras this area
will vary depending on the distance from
the camera to the subject and the type
of lens being used. A
field of view calculator is used to
determine the field of view with various
distances and lens settings.
||Focal Length tells you the strength of the lens. The longer the Focal Length the narrower Angle of View, the shorter the Focal Length the wider the Angle of View.
||Frames Per Second - in digital video
applications, refers to the number of
video images that can be captured,
displayed, or recorded in a second. Also
referred to as the 'frame rate' or
||Covering or container featured on some cameras designed to protect from it from the weather.
||Infrared radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red", red being the color of visible light with the longest wavelength.
Security Cameras have special infrared lights installed around the outside of the camera lens. Through use of this special light the camera can capture a good picture even in total darkness.
Address is a unique address given to
certain computer or electronic devices.
An IP address is necessary for devices
to identify and communicate with each
other. An IP address is required for
positive unique identification of any
device on a network or the internet.
||The Iris (on some lenses) controls how much
light is let into the camera lens.
|JPEG (or JPG)
||Pronounced "jay-peg" and stands for
"Joint Photographic Experts Group" who
designed the standard. This is a
standard way of compressing images which
works particularily well for
photographic images (as opposed to
The lens of the camera determines
the angle of view (Field
of View) and the focus of the
captured image. There are many different
||Refers to very dim lighting, even
'normal' darkness. Complete darkness is
Infrared cameras work well in
very low light conditions.
the amount of light required for a
camera to capture a good image. Infrared
cameras have very low lux.
||Very small cameras designed to work
in covert applications where you don't
want people to know that the camera is
there. Also called 'hidden cameras'.
||Security camera monitors are used to display the images captured by your cameras. They come in analog and digital versions.
||A feature in some VCRs and DVRs to only begin recording video if something in the image moves or changes. Good for monitoring an area that is not heavily trafficed, and saves a lot of hard drive space.
||Various different kinds of mounting
brackets are used to install cameras to
the wall or ceiling.
|MPEG (or MPG)
||Pronounced "em-peg" and stands for
"Motion Picture Experts Group" who
designed the standard. This is a
standard way of compressing audio and
video files. (It's also the technology
behind the now world-famous MP3 music
A device that can accept a number of
camera inputs and almost simultaneously
display them on a single monitor and/or
record them. Multiplexers can also be
used to transmit multiple cameras over
the same transmission medium.
||Outdoor cameras come in special
weatherproof housings that allow them to
stand up well in tough weather and
Pan-Tilt-Zoom (PTZ) Cameras
||PTZ cameras allow you to adjust the
position ('pan' is side-to-side, 'tilt'
is up-and-down) and focus ('zoom') of
the camera using a remote controller.
Due to this added functionality, these
cameras tend to cost much more than
||Pin-hole cameras have a very small
lens that can see through a small hole.
These types of cameras are used in
covert applications. A disadvantage of
pin-hole cameras is that they require
more lighting than normal cameras to
capture a good clear picture.
|Plug and Play Cable
A cable that makes wiring cameras
easy. Each camera needs to have a power
wire and video wire (and sometimes an
audio wire too), plus the connectors at
the end of the wire to plug it in. The
plug and play cables have all three
wires built into one cable with the
connectors already attached. The only
disadvantage of plug and play cable is
that the signal tends to degrade if run
distances. For DVRs - plug and play
cables can be run reliably up to 100 ft.
For analog systems - plug and play cable
can be run up to 400 ft. If you need to
run longer distances then you need to
use the RG59 Siamese cable.
||Power Over Ethernet - an adaptor
that allows you to transmit power to a
security camera through CAT5 (aka
||This is a DVR's ability to record after a motion detection event has occurred. It records for a specified amount of time after the event has been triggered, even though the motion may have ceased.
||See: AC Adaptor - All CCTV devices require power of some sort. Electricity in the United States comes in one form, 110 to 120 AC. The AC adaptor converts the AC power to DC power and will adjust it to a specified amperage. Power supplies should come included with each item.
||Pre-record is a setting on DVR systems that applies to motion recording. Normally, when a DVR is set to record motion, it takes a second ro begin recording once the motion has been triggered. With pre-record selected, a buffer of the previous 140 frames before motion was triggered is recorded to the drive, allowing the security camera to capture one or two seconds prior.
||Pan-Tilt-Zoom - PTZ cameras allow
you to adjust the position ('pan' is
side-to-side, 'tilt' is up-and-down) and
focus ('zoom') of the camera using a
remote controller. Due to this added
functionality, these cameras tend to
cost much more than non-PTZ cameras
analog device used to display 4 cameras
simultaneously on a single monitor.
||An RG-59 is a common co-axial cable used
in CCTV applications.
|RG59 Siamese Cable
This type of cable combines the power
wire with the video wire. You have to
add your own connectors to each end of
the cable. Use this type of cable when
you need to run distances longer than
100 ft with a digital system, or more
than 400 ft. with an analog system.
||An electrical connector invented by Radio Corporation of America, from which its name is derived. Consists of 3 wires - red, yellow, and white, these are commonly used on a wide assortment of products in the audio/video market.
||In digital video applications, 30
frames per second per camera (see above)
looks just like real-time. There is no
hesitation or jerkiness in the video.
The ability to view your cameras
from a remote location. Information is
transmitted via phone line or internet.
Refers to how much detail can be
captured on a camera or displayed on a
monitor. Cameras typically capture about
380 horizontal lines of resolution. High
resolution cameras may capture 450 lines
of resolution or more. The higher the
resolution, the more detail that can be
captured in a picture. The monitors and
recording devices can generally handle
at least as much resolution as the
cameras can capture.
||This is a feature of our digital
video recorders that allows you to
search for changes in a particular area
of an image over time. For example, if a
wallet was stolen off of a table, you
could go to a point on the video where
the wallet is there, draw a virtual box
around that area, then search the video
recording for changes to that particular
area. This would allow you to locate the
exact point on the video where the
wallet was removed.
||Signal to Noise Ratio; this number
represents how much signal noise the
camera can tolerate and still provide a
good picture. The higher the number the
switch will take multiple camera inputs
and will show them on the monitor one at
a time. Unlike a quad it will not
display them all at once, instead it
sequences through them showing one
camera at a time. It will also allow you
to select a particular camera to view.
||A VCR that can be set to slow down
its recording rate in order to extend
the length of time that can be recorded
on a standard tape up to as much as 960
hours. This is possible by recording one
frame at time at set time intervals.
Most units have an alarm input signal so
it can be automatically switched to real
time mode in case of an alarm.
A device used to transfer electric
energy from one circuit to another,
especially a pair of multiply wound,
inductively coupled wire coils that
effect such a transfer with a change in
voltage, current, phase, or other
A camera lens in which the focus is
not fixed, it can be manually or
||Videocassette recorder; an
electronic device for recording and
playing back video images and sound on a
||VHS (Video Home System) is a
widely-adopted videocassette recording
(VCR) technology that was developed by
Japan Victor Company (JVC) and put on
the market in 1976. It uses magnetic
tape 1/2 inch (1.27 cm) in width.
Originally, the abbreviation VHS stood
for Vertical Helical Scan, and was later
changed as the technology gained in
Video Capture Card
|Computer cards that you can install
on the motherboard of your own computer
to create your own video recording
computer. Due to compatibility issues
with this type of device, we do not sell
||An increase in video signal power by
an amplifier, expressed as the ratio of
output to input. Also called
||A connection in a video controller
or recording device that you can plug a
camera into. The more video inputs (also
called camera inputs) available on a
device the more cameras you can connect
|Watch Dog Timer Circuit Protection
||If problems are detected in the DVR
computer the system will automatically
reboot to correct the problem.
A device that can be immersed in
water and still function properly.
A device that is weatherproof can be
installed outside and stand up to harsh
weather conditions and temperatures.
However, it does not mean that it is
||Wireless cameras allow the
transmission of video and audio data to
be transmitted to the receiver without
having to run wires (using radio waves).