Cameras

Specification of the right CCTV camera for a project is not always the easiest of processes. There are many factors that have to be taken into account: technical specifications, the application and its requirements, as well as any physical constraints the site may impose. With ever increasing product ranges available in the marketplace, and technology constantly evolving to optimize performance, reliability and functionality, it is quite a challenge to make an informed decision to meet the requirements for the job while remaining within your projected budget. Understanding the many variables within CCTV camera technology today can only be an advantage in helping you make the right choices.

At the heart of the CCTV camera technology is a CCD sensor (Charge Coupled Device) that converts light into an electrical signal. This electrical signal is then processed by the camera electronics and converted to a video signal output that can then be either recorded or displayed on to a monitor.

However, the treatment of the video signal is then dependant on the type of camera. CCD chip cameras can be divided into two principal types: analogue or the more recently introduced digital versions.

Analog vs. Digital

Until recently most cameras have been of the analog type, producing good quality images at an affordable price. However, the introduction of Digital Signal Processing (DSP) has increased both the flexibility of using security cameras while enhancing the quality of the color images produced.

At the heart of DSP lies computer microchips, or 'chip sets' which have replaced the conventional integrated circuits in the camera head. This enables DSP camera manufacturers to offer installer friendly, feature-rich products.

The market for DSP technology falls into two broad categories: 'standard' and 'premium' DSP. Standard DSP cameras generally offer more consistent picture quality than their analog counterparts, operating over a wider range of lighting conditions. Premium DSP cameras, however, have much richer functionality. This includes programmable intelligent backlight compensation (BLC), Video Motion Detection, remote set-up and control using a serial data link; built-in character generator and on-screen menus. These features make Premium DSP cameras the ideal choice for complex surveillance conditions such as those encountered in town centers.

Color vs. Monochrome

The human eye remembers and recalls things better if they appear in color - it's easier to track down a brown-haired person wearing a red sweater and blue jeans than a dark, gray-clad figure that would be produced in monochrome.

Color cameras carry an additional premium in price compared with monochrome cameras. But they are also less sensitive making night usage an impractical option unless good lighting is available.

Monochrome cameras can offer Infra Red (IR) sensitivity allowing their use with covert IR illumination possible. This can be particularly useful where planning permission makes extra lighting impractical or the security requirement is such that intruders should not be alerted to the existence of CCTV surveillance.