CCTV technology has changed over the years since its inception in the 1940s, electronics have become more advanced and more compact each year and cameras are now commonplace in most streets and businesses.The early “noughties” saw cameras being produced with colour electronics and a move from tape recording systems to digital video recorders saving footage on hard drives.Since that time, picture resolutions and recording quality have all improved but there has been little in terms of major changes in the industry until the last couple of years. HD-SDI and IP CCTV are the new kids on the block so what does it all mean?
Most CCTV systems you will see out and about are analogue CCTV cameras and analogue recording devices. The “analogue” technology has been the CCTV staple for many years now and still is a perfectly adequate technology for many installations where general surveillance is required. However Analogue lacks the stunning high definition picture quality of HD-SDI and some IP CCTV systems. As many end-users are used to home HD TV at home, HD-SDI is now being adopted by many installers to live up to end user expectations.
The latest 100% digital technology that gives superb picture quality and is an easy upgrade path for an analogue CCTV system as it uses the same co-ax cable and many of the same accessories. HD-SDI pictures can be up to 20x better than an analogue image so it is ideal for identification of criminals and similar applications that require an excellent picture quality. Gives end users a CCTV system that’s of similar quality to the HD home TV they are used to. Because the installer can use their own co-ax it’s far easier to insist the customer does not interfere with the CCTV system unlike IP CCTV which may use the customer’s own LAN.
Another high definition alternative to analogue that is popular for new installations as it can use a building’s existing IT network to transmit CCTV images from one location to another. IP is quite liked by some installers as it can share the customer’s existing LAN but this can be as much a curse as a blessing. Often the LAN is not fast enough for the huge bandwidth required for IP CCTV and the installer can’t stop the customer altering or tinkering with their own LAN after install! This can result in call backs when the cameras don’t work properly due to “bottle necks” on the LAN. As IP cameras sometimes reside on a customer’s LAN, it’s not officially a “CCTV” system anymore as this refers to “Closed Circuit Television System” and the LAN actually Opens it up! Maybe it should be called OCTV IP! Some IT departments also don’t like the vulnerability of sharing the LAN with CCTV equipment. Here are a few of its pros and cons.