CLOSED CIRCUIT TV
CCTV (Close Circuit Television) has been around for a very long time. I remember the days when low resolution cameras were the size of an average cat and as heavy as a small car battery. When recordings were made on Sony video recorders on Betamax tapes as well as on National Panasonic video recorders using VHS video tape amongst the several standards and video machines that existed during this time. However their metalic coated cellulose video tapes had a finite lifespan because they lost their coercivity through constant use and if the footage somehow got tangled in a video machine it was normally damaged and subsequently unusable or very difficult to recover.But those days are now are far gone and the CCTV industry has matured. Cameras have gone from low resolution TVL to high TVL resolution analogue (CVBS) cameras, (AHD) cameras, to Multi Megapixel CMOS, TVI, HD-CVI digital cameras constantly decreasing in size and increasing in resolution. The trusty video recorder has given way to the DVR which essentially is a dedicated digital recorder with at least a half a Terabyte hard drive with dedicated software to oversee CCTV footage recording and playback. The latest DVR's are even networkable and can plug into Netgear / Cisco/ HP switches / routers and serve as a server serving its content to the Internet which is viewable by account holders with the correct login credentials.
Cameras now come in varies shapes and sizes with features unheard of just a few years ago. WDR (Wide Dynamic Range) cameras and NPR (Number Plate Recognition), FR (Facial Recognition) are some some of the marvels out there for Industrial/ Commercial use, however there is a huge range of video cameras manufactured especially for the domestic market. A CCTV installation can be done using either Ethernet Cable (CAT5/6) with bayluns or with RG58 coaxial cable with an additional / seperate power supply cable or using powerax (RG59 cable). Coaxial cable are normaly connected to the DVR or with BNC (British Naval Connectors) whereas the bayluns have BNC connectors on their pigtails.
Today with the high level of crime, a CCTV home surveillance installation is almost a necessity and is quite simple to do especially since DIY kits are now going for "a dime a dozen". I've used a few of these DIY kits on commercial applications where it was supplied by the client who bought them on online auctions. In my opinion, they are not a good fit for commercial use because the cameras don't have vari-focal lens, rather fixed with a fairly narrow viewing angle. I suppose for domestic use they would be OK but personally I wouldn't buy them because these DIY kits are normally obsolete stock, low end cameras that nobody wants to buy or in favour of the latest technologies. I always recommend the client buys the best and latest technology that he can afford because it takes so much longer for it to be superseded whereas some of these DIY kits have been superseded by several newer models.
These DIY home surveillance kits come in 4 Ch, 8 Ch and 16 Ch many of which are QR Code enabled for quick remote access connectivity to the manufacturers free DNS service. As can be seen the kit in the image above comes without a VGA monitor and power supply so care should be taken to ensure all the necessary components are included before biding for it on any online auction.
