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 high priced but are great for cameras that may require
vision in near darkness.

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 over time, 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 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.

WHAT IS A DVR CARD?

DVR Cards enable the user to convert their computer into 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.  WE SELL THE DVR CARD ONLY.  
THE CUSTOMER IS RESPONSIBLE FOR INSTALLATION AND THEIR OWN COMPUTER.

DO YOU NEED A VCR OR DVR TO RECORD?

You must have a VCR or DVR to record.  

WHAT IS A VARIFOCAL LENS?

A varifocal lens is where the focal length of the lens can be varied.  This is the same thing as a
zoom lens.  Most varifocal lenses have an auto iris feature.

WHAT IS THE OPERATING VOLTAGE OF A CAMERA?

Our cameras range from 9 volts (CMOS) to 12 volts and also 24 volt professional models.

SURVEILLANCE DEFINITIONS:

CMOS:  Complimentary Metal Oxide Semiconductor:  a lower resolution camera compared to
a CCD model.  The advantage of a CMOS camera is that it uses lower operation current.

FOCAL LENGTH:  The distance from the surface of a lens and its focal point.

RESOLUTION:  Resolution measures the cameras ability to reproduce an image.  The
higher the resolution, the better the picture quality.

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 30 fps for each camera.

VIDEO COMPRESSION:  Refers to reducing the quantity of data used to represent digital
video images.  Compressed video can reduce the bandwidth required to transmit video via
broadcast, cable TV, or via Satellite TV.  Video compression is a tradeoff between disk space,
video quality and the cost of hardware required to decompress the video in a reasonable time.  
For example, DVD's use a video coding called MPEG-2 that can compress around 2 hours of
video data by 15 to 30 times and will still produce a good video.
Types of Video Compression:
MPEG-2    DVD Quality
MPEG-4    Streaming media video conversation, broadcast TV
H.264        Blu-ray Disc

LUX:  Refers to the SI unit of illuminance and luminous emittance.  It is a measure of the
intensity of light in an area for devices requiring light.  Security cameras uses lux to determine
the minimum amount of light needed in an area for video surveillance.

LUX                           Example
0.0001                Overcast night
0.001                  Starlight
0.0108                Quarter Moon
0.108                   Full Moon
1.08                     Deep Twilight
10.8                     Twilight
107                      Very Dark Day
1075                    Overcast Day
10752                  Full Daylight
107527                Sunlight

LED'S:  Stands for light emitting diodes which are semiconductor light sources.  LEDs are
used as indicator lamps in many devices, and are increasing use for lighting.  Security
cameras use infrared LEDs for illumination during nighttime operation.

VARIFOCAL LENSE:  Is a camera lens with variable focal length in which focus changes
as focal length (and magnification) changes.  Many so called "zoom" lenses, particulary in the
case of fixed lens cameras, are actually varifocal lenses.

AUTOMATIC IRIS LENS:  Is a lens in which the aperature automatically opens or closes to
maintain proper light levels on the camera pick up device.  The aperature is the opening in the
camera that controls the amount of light that reaches the camera.

INFRARED CUT FILTER:  A day and night camera uses an infrared cut filter during the day
to filter out the infrared light so as not to distort the colors of the image.  At night, the camera
switches to night mode (black and white) and remove the infrared cut filter allowing the image
sensor to capture high quality images.

IP CODE:  The IP Code or Ingress Protection Rating classifies the degrees of protection
provided by the camera housing against the intrusion of solid objects (including body parts
like hands and fingers), dust, accidental contact and water.  The IP Rating gives more detailed
information for the term "waterproof" when referring to cameras.


BROUGHT TO YOU AS A SERVICE OF AMERICAN SURVEILLANCE
CONSULTANTS,LLC
TO PROVIDE OUR CUSTOMERS WITH A BETTER
UNDERSTANDING OF THE TECHNICAL TERMS AND WORDS
USED THE FIELD.
FAQ's
This Windows based DVR allows
you to install up 16 cameras and
digitally record all activity.  It has
full networking capabilities.
FAQ'S-SURVEILLANCE SYSTEMS
AMERICAN SURVEILLANCE CONSULTANTS,LLC
CALL FOR YOUR FREE SURVEILLANCE SYSTEM CHECKUP

727-422-7321
On This Page:
What is CCD?
What is the difference between DVR
and VCR?
How many hours will a DVR record?
What is a DVR Card?
What is a Varifocal Lens?
What is the operating voltage of a
camera?
Other Surveillance Definitions
including CMOS, Focal Length
Resolution, FPS, Video
Compression, LUX, LED's and IP
Code.