Sunday, December 30, 2012

CCD Chip Introduction

  A CCD(charge coupled device) composed of thousands of individual pixels with a tiny 1/2", 1/3", even 1/4" chip. Each pixel responds to light falling into it by storing a tiny electricity charge. The pixels locate on a precise grid which consists of vertical and horizontal transfer registers sending the signals to the CCTV cameras's video processing circuit. This transfer of signals occurs sixty times per second.
  Currently, The 1/3" CCD chip becomes the most popular sensor format, the dimensions are 4.4mm (horizontal) and 3.3mm (vertical) and 5.5mm (diagonal). The 1/4" sensor format which is 4mm (diagonal), 3.2mm (horizontal) and 2.4mm (vertical), is widely used in color cameras.The Electronic Shutter of CCD chip plays a leading role to produce a wonderful and reliable picture.

CCD and CMOS(complementary metal oxide semiconductor) sensors are the different digital technologies for capturing image. They both have strengths and weaknesses in various applications.

Wednesday, December 26, 2012

The resolution of CCTV system

  The resolution of CCTV cameras system is usually measured by TV lines. The vertical TV lines is fixed and the maximum is 350 TV lines in 525-line NTSC system. However, as the parameter of image quality, the horizontal TV lines depend on the quality of camera, lens, transmission and monitor.

Camera Resolution
  Pixels is used by the industry of CCD video camera sensor as it's quality parameter. in EIA system, Medium resolution of B/W camera is 510 horizontal pixels and 492 vertical pixels which equals to 380 TV lines. High definition is 768(H) x 492(V) pixels and equivalent to 570 TV lines. Color camera's medium resolution is 330TV lines and high resolution is over 460 TV lines.

Monitor Resolution
  The monitors in NTSC system have 525 vertical scanning lines in spite of their size. in EIA system, The horizontal 700 TV lines of B/W monitors represents medium level and over 900 TV lines means high resolution. The color monitor's horizontal resolution of 300 TV lines represents medium quality and over 450 TV lines resolution represents high resolution.

  For the sake of system's resolution, we suggest select a monitor which has better resolution compared to your camera.

Tuesday, December 25, 2012

what is CCTV?

  CCTV, Closed Circuit TeleVision, is really a TV system which doesn't broadcast TV signals to public but transmits them over to limited monitor(s). CCTV cameras system usually uses CCD video cameras (to create the video), cable or wireless transceivers or Internet (for video transmission), and monitors (to watch the video). CCTV system is mainly used for surveillance purpose, besides, it can also in other fields like laboratory in schools or in private companies, even the production lines in factories. Along with the usage of CCTV system increased, various CCTV equipment, such as Time Lapse VCRs, combiners, infrared illuminators, Pan/Tilt, are developed. The newest development is web camera server utilizing the web for remote surveillance.

Sunday, December 9, 2012

Fake or real security camera? how to choose

A well designed video CCTV system can prevent crime and provide invaluable information after a theft or attack. Rather than install the proper cameras for safe, some persons just hang "fake" cameras on the buildings, even worse, some providers suggest that they do so. 
Just as a corn has two sides, fake cameras have advantages and shortcomings. Fake cameras are very economic compares to real surveillance, and in some ways, it have effects. However, if you want to provide real protection, please choose real CCTV cameras. There are some factors as follows you need to pay attention.
Fake Cameras Can Do Nothing. The fake cameras can’t record activity. They just hang there on the building, nothing can do. So do not waste the money and effort. Besides, some fake cameras are so “fake”, you can easily tell the ture and fake cameras at a glance.
·         In some cases, some people mix the real and fake cameras in a single surveillance camera system and believe they can be effective. But the Things go athwart, Putting real and fake cameras near each other means ” I am a fake camera”, some trained folks can know exactly where you're not monitoring..

·         All in all, If your business needs protection, take some time to choose proper CCTV cameras and cover the areas that require surveillance. If you are just want to play a trick, the economic fake camera is your best.