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CCTV | DVRs | DVR Storage Capacity Calculator | VCRs

Monitors | Cameras | Lens Size Calculator | Camera Power And Cables

CCTV Physical Security Tutorial


NOTE: Information compiled from Wikipedia and other public domain sources

What is CCTV? - Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific, limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point wireless links. CCTV is often used for surveillance in areas which need security, such as banks, casinos, and airports or military installations. In industrial plants, CCTV equipment may be used to observe parts of a process that are remote from a control room, or where the environment is not comfortable for humans. CCTV systems may operate continuously or only as required to monitor a particular event. CCTV is becoming popular for home security systems.
Example of CCTV Setup
CCTV Example


DVR Example DVRs / Digital Video Recorders - View Our Selection Of DVRs
DVRs function similar to VCRs. They record images directly to a hard drive. There are no tapes to manage. Some DVRs come with a CDRW or DVRW which allows recordings to be burned on to CD's and DVD's. DVRs can be a stand alone product or can be a seperate card and software that can be installed on a computer. Every DVR is unique so review the available documentation before ordering. Important things to know when deciding on a CCTV DVR to purchase:
  • Hard Drive (HDD) - The more hard drive space the more hours of recording are available. See our DVR Hard Drive Calculator below for more information.
  • Channels - The number of available recording inputs for cameras.
  • Remote Surveillance - Allows the video on the DVR to be viewed from remote locations by using the internet or a LAN.
  • Video Format - MPEG4 is the standard format for digital recording.
  DVR Storage Capacity Calculator  
  Please choose the following options:  
  Recording Quality:  
  Picture Quality:  
  Recording Speed:  
  Recording Time:  
   
 
 
  HDD Size:GB  
  Tips
  • IPS = Images per Second @ Full Recording Resolution ex. 720*240
  • 1/1 is the highest recording frame rate. 1/1 = 30 FPS (Frames Per Second), 1/2 = 15 FPS, 1/3 = 9.9 FPS, etc.
  • In regular situation, 1/10 is the most acceptable recording speed
  • All cameras share the Maximum Recording Frame rate
  • Picture Quality: This refers to the image file size.
    • Basic 12 KB/field
    • Normal 16 KB/field
    • Enhanced 20 KB/field
    • Fine 24 KB/field
    • Super Fine 28 KB/field
    The higher quality pictures require more hard space to store the information.

This calculator is for your reference only. The actual size may vary because of different Hard Drive Specification.
 
 
 

VCR ExampleVCRs / Video Cassette Recorders - View Our Selection Of VCRs
Security VCRs / Video Cassette Recorders record video and audio on VHS cassettes. Security VCRs are specially designed for longer recording times and compatibility with security cameras and CCTV systems.

Monitors - View Our Selection Of Monitors
Monitors display the images from the security cameras. Many of the monitors have camera inputs built directly into them. If you want to hook up more cameras than direct input cameras you need to use a video matrix. Monitors come in color and black and white (B/W). A video monitor has no tuner and, as such, is unable to independently tune into an over-the-air broadcast Important things to know when deciding on a monitor to purchase:
  • CRT = Cathode Ray Tube style monitor. LCD = Liquid Crystal Display monitor.
  • NTSC = The TV signal used in America and most of South America. PAL = The TV signal used in the UK and other countries.
  • Lines = The higher number of lines across the screen the better the picture quality.
  • Channels = The number of direct camera inputs into the monitor.

Camera ExampleCameras - View Our Selection Of Cameras
Cameras capture images and sometimes sound and send the data to the monitors and recording devices. The most common styles of cameras are bullet cameras and dome cameras. Certain cameras are designed for indoor and / or outdoor use, and some are bullet proof and vandal proof. You can mix and match cameras as long as they use the same input cables. Important things to know when deciding on a monitor to purchase:
  • IR LED = Infrared LED, allows the camera to see in the dark.
  • IR Distance = Infrared Distance, how far the camera can see in the dark.
  • LUX = Illumination Rating, the amount of light required for a camera to capture in image. The lower the LUX, the less light that is needed.
  • Vari-focal Lens = Allows view angle and the object distance to be changed.
  • Field Of View = The height and width of the image seen by the camera in relation to the distance. Use our tool below to calculate the Field Of View you want to help you determine the correct lens size.
  • CCD Format = 1/3 Inch or 1/4 Inch CCD. (Charge Coupled Device) This converts images and sends it to the monitor and recording device. 1/3 Inch CCD is the most popular, it's larger size allows more light to be captured. Although to the naked eye many people can't tell the difference in quality, 1/3 Inch would be preferred for monitoring dimmer areas.
  • PTZ = Pan, Tilt, Zoom. A PTZ System allows the cameras to be remotely panned, tilted, and zoomed. In addition to special PTZ cameras you also need PTZ controllers.
  Lens Calculator - View Our Selection Of Lenses  
 
 
  Select the CCD Format: 1/4 inch CCD
1/3 inch CCD
 
 
 
  Enter any 2 of the 4 fields:(distance, width, height and lens size)  
  Enter distance to object (in feet):  
  Enter width of picture (in feet): or  
  Enter height of picture (in feet):  
  Enter size of lens (in millimeters):  
 
 
  Press the "Calculate" button to get the missing piece of information. (Press the "Reset" button to clear the form and start over.)   
 
 
  Lens Field Of View  

Camera Power and Cables
Power Regulators can be used to power each individual camera. If the power source is near the monitor, Siamese Cables can be used. These special cables have a power wire in addition to video and audio wires, to go from the monitor area to the camera. There are also wireless CCTV systems and accessories available.



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