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.
DIGITAL VIDEO RECORDERS
The trusty domestic, vintage, analog, time-lapse Video Cassette Recording (VCR) format, initially designed by Grundig/Philips has been around for a number of years. I still remember the incompatible Phillips (2000), Sony (Betamax), Panasonic (VHS), etc. Video recorders of the '80s. Each with their 1, 2, 3 and 4 hour video cassettes, boasting abilities to record at half speed, thereby multiplying the length of the magnetic tape by at least two, allowing a 4 hour tape to record an 8 hours video stream Their industrial versions were universally used in the security sector, in hospitals, prisons, large corporations and in the homes of the wealthy. The tedium of reviewing the recorded footage was always time consuming because of the linear nature of magnetic video tapes. Although footage on these these helical scan machines could be viewed in fast forward it decreased the life of the magnetic tape substantially requiring replacement every so often. Tangling tapes were another issue to contend with because it destroyed the quality of the images on the tape.
Making a copy of any security incident from the magnetic tape was also a challenge, which required a second machine, a length of RG58 coaxial cable with BNC (British Naval Connector) connectors at either end, a screened cable with RCA (Radio Corporation of America) connectors or some other manufacturer specific connector that was the order of the day. There was little standardization among, Panasonic, JVC, Mistubishi, Magnavox, Sanyo, Hitachi, Akai, Funai, Goldstar, Kenwood, Lloyds, NEC, Orion, RCA, Toshiba, Sharp, Sansui, etc. other than their common Beat or VHS format. However, storing security tapes was the biggest hassle, besides cataloguing and labeling, they required a temperature controlled storage area to stop the cellulose based magnetic tapes from disintegrating. Today, CDs can store data for periods of time in excess of 50 years.
The PAL/NTSC CVBS (Coulour, Video, Burst & Synch) cameras on the other hand weren't very high end either when compared to what's on the market today. They were also bulky, often black&white and none of these cameras came close to the 625 lines except for broadcast cameras which were in a totally different league completely. Having said that, technology advances in leaps and bounds and as a consequence older technologies just fall by the wayside. It you had an 8 track car tape player, or a domestic turntable, or a Hi-Fi system, all of which has been superseded by CD/DVD players, thumbnail flash drives, and computers then you know exactly what I mean. So today, it is almost impossible to find monochrome cameras, reason being we live in a colour world and the processors used in the cameras are churned out in the millions by chip manufactures, making the lives of the camera manufactures a walk in the park.
To return to the topic of Digital Video Recorders, or DVR for short. Digital Video Recorders (DVRs) has taken the security sector by storm and several manufacturers have cottoned-onto the lucrative nature of the security business. But standardization is still an issue. Currently the state owned Chinese Digital Video Recorders (DVRs) manufacturer HikVision www.hikvision.com seem to be the CCTV / DVR / Camera market leader, closely followed by Dahua www.dahuasecurity.com, followed by Israeli Digital Video Recorder (DVR) manufacturer ProVision www.provision-isr.com. However, this is purely based on popularity and price and not neccesarilly on quality and functionality because there is also a huge badge engineering market out there. It appears that at least a dozen "Digital Video Recorder (DVR) manufacturers" are also selling cloned Dahua products but under their own names. Perhaps Dahua manufactures for them only attaching there badges. Among them are, HangBang www.hbgk.net, Swann www.swann.com, Sanan www.sanan-cctv.com, Xenon www.xenon.cn, LB-Tech www.an-tone.com.cn, and Longse www.longse.com, etc.
The far east and asia seems to have always had the edge of technology because they may not be great inventors but definitely the best of innovators. Case in point, the wrist watch may have invented the Swiss/Germany clock-maker but the Japanese company Seiko came to perfect it quarts kinetic. Admittedly Swiss watches like Rolex, Tudor, Tissot, Rado, Breitling, Piguet, Omega are really amazing and are made for the wealthy with disposable incomes, watches like Casio, Citizen, Orient, Sea-Gull, Fiyta, Rossini, from the east are giving them a run for their money.
Then there is the first car invented by the American Ford motor company but massed produced for the man in the street my Korean (Hyundai, Kia, Daewoo) and Japanese (Toyota, Nissan, Honda, Mitsubishi, Subaru). Then there is the first model of the Kodak camera invented by American George Eastman but Japanese camera makers Nikon, Canon, Mamiya, Minolta, Olympus, Fuji dominates the photographic market.
Italian inventor Guglielmo Marconi, was renown for manufacturing the first radio but since the radio market has been taken over by Sony and most other Asian manufactures like Hitachi, JVC Kenwood, Mitsubishi Electric, Nintendo, Sharp, TDK, Toshiba and Yamaha, etc. So its no surprise that the security Digital Video Recorders (DVRs) / Camera industry is now dominated by the Asian market.
Anyway, the modern day incarnation of these magnetic tape based Analogue Video Recorder is the all new software driven terabyte hard drive based, light weigh, low component count, Digital Video Recorder / Internet server. No more damaged footage due to tangled tapes. No more footage viewing tedium since hard drives stores data in individually accessible sectors. Copying footage is easily done by just dragging a footage selection onto a flash drive. Camera views can be automated without the need of electronic switching equipment needed in yester year.
Access can be managed through strong passwords and the Digital Video Recorders (DVRs) entire operation can be controlled via a mouse driven GUI, even remotely across a computer network. Remote viewing through the Internet is one of its key features and a strong motivations for small and medium sized businesses and to buy into the whole security Digital Video Recorders (DVRs) idea. Even though the entire concept of the DVR is still based on magnetic coercivity, the key difference is virtual instant access to footage because of hard drive storage. Analgue circuitry designed and built from discrete electronic components turned out bulky whereas digital circuitry based on LSI microprocessors and video compression algorithms used in DVRs are comparatively miniscule. With the rapid reduction in data storage costs the DVR became a reality, affording us better reliability, scalability than an tape based solution. And this is just the beginning. IP based high resolution cameras and multi-site NVR based security system running on CAT-6 are already replacing technology that only saw the light of day less than 10 years ago.
