An analogue CCTV camera begins with a CCD sensor and then digitizes the image for processing. But before it can transmit the video, it needs to convert it back to analogue so it can be received by an analogue device, such as a video monitor or digital video recorder (DVR). Unlike IP cameras, analogue cameras have no built-in web servers or encoders and require no technical maintenance. These functions are implemented in the recording and/or control equipment.
Benefits of analogue over IP technology include:
Analogue CCTV systems are often less expensive overall
Analogue CCTV products are at this point in time still cheaper than their IP counterparts – NVRs can be twice as expensive as a DVR for example. The installation of an analogue surveillance system can also be less expensive because they are quicker to install with minimal network set-up and configuration.
However in some situations a single IP camera can be installed in the place of a number of standard CCTV cameras so we always recommend looking at both options before making a final decision.
Analogue CCTV systems are easier to maintain
Overall standard CCTV security systems need little maintenance once installed. We recommend a basic check once a week to confirm all cameras are recording and footage can be retrieved from the DVR.
Because an analogue system is not attached to the business or home network it won’t be at the mercy of network issues. Large file sizes, limitations to the bandwidth, viruses or too many devices trying to use the network (congestion) are just some of the challenges facing the installation and ongoing maintenance of an IP system.
Analogue CCTV cameras can perform better in some environments
Depending on the environment an analogue security camera may perform better than an IP camera in the same position. Situations where this may occur include:
Low light: The CMOS image sensors normally used in IP cameras deliver great HD resolution but do not handle low light very well. Some IP cameras will produce a grainy picture at low light (which also uses up bandwidth and storage space because it is interpreted as motion). Many analogue cameras use a CCD image sensor which has much better low light performance.
Darkness: Most analogue surveillance camera include in-built IR (infrared) that allows the camera to record images even in complete darkness. While IP cameras will record down to a very low level of light if they need to record in zero lux separate IR illuminators will need to be installed.
Fluorescent lighting: Fluorescent lighting is used in many indoor spaces in and it can create problems, particularly for IP cameras. The frequency of the fluorescent lighting and the power source can clash which creates a constant flicker on the live and recorded video image. Accurate colour information may also be affected. Note that this problem can also affect some standard analogue CCTV cameras with CCD image sensors.
Longer cable runs with analogue CCTV cameras
IP camera cable distances are limited to 100 metres between the camera and network switch by structured cabling regulations. It is possible to run Cat5 cabling that will allow analog cameras to be mounted up to two kilometres away from the DVR.
Mix and match analogue surveillance products
Virtually any standard CCTV camera will plug in to any DVR allowing you to easily customise and upgrade your system. An IP surveillance system is set up specifically to work with the network protocol it is designed for. This means different IP camera and NVR brands may not be compatible.
View footage in true real time
Because the image from a standard CCTV camera is processed and compressed at the DVR (not the camera) it can be viewed live with no delay. IP cameras can experience ‘lag’ for up to 2-seconds.