When deciding on having a CCTV system installed customers often ask why there can be such a price difference in systems, especially between Analog DVR and IP NVR based systems, I hope the information below is of use in helping you decide on the correct system for your premises.
CCTV - DVR or NVR - Which should you choose?
There are two main types of wired CCTV systems, one is based on a DVR (Digital Video Recorder) and the other is based on a NVR (Network Video Recorder) So which is best for your requirements?
DVRs and NVRs both capture video received from the camera. A DVR system processes the signal within the DVR itself while an NVR system completes the process at the camera which streams the information to the NVR. DVRs use analog cameras and NVR’s require IP cameras.
DVR CCTV System
Analog technology has advanced over the last few years and there is now not much difference between the resolutions of each system. The cost saving on a DVR system is due to the fact they use analog cameras which are much cheaper than their IP equivalent. Whilst analog cameras capture excellent images there are limitations in what the cameras can actually do, due to all the processing being completed at the DVR.
DVR’s have also improved considerably, there are now video analytics such as Line Crossing and Area Intrusion that can be set up for each camera. Analog cameras can also be wired in Cat5 cabling utilising video baluns (a balun converts the video signal) A separate pair of the Cat5 cable is then used to provide power, usually from an encapsulated power supply installed next to the DVR. The advantage being that the cabling can then be utilised for an NVR / IP system in the future should you consider an upgrade.
For small residential properties a 5MP Analog Camera system with a DVR is usually sufficient and certainly more cost effective than installing a full NVR / IP system.
NVR CCTV System
NVR / IP systems are certainly more flexible, the majority now utilise POE (Power Over Ethernet) This means the cameras are powered direct from the NVR via Cat5 cabling without the need for a separate power supply. This works on a basic system however as technology has advanced should you install a camera with multi functions such as pan, tilt zoom or even the recent ColourView 24/7 Colour Cameras then a separate POE Injector is required to give the camera its full power requirements, think of a POE injector as a camera power supply!
NVRs also receive a pure digital signal from the cameras which is of a better quality than a DVR at the same resolution however images from both systems are more than adequate for CCTV surveillance, especially in a domestic set up.
Cameras
Analog cameras are certainly limited in functionality however on the majority of domestic installations this is not an issue. As noted previously the latest DVRs now have functions built in such as ‘Line Crossing’ and ‘Motion Detection’ which work very well in a domestic situation.
IP Cameras are certainly more flexible due to a wealth of functions they can perform, from facial / number plate recognition, temperature sensing, line crossing, people counting etc etc, however the technology comes at a premium, IP Cameras by their very nature cost significantly more than their analog counterparts.
As NVR recorders receive a pure digital signal from the cameras, video quality is better than compared to a DVR receiving an analog signal at the same resolution however the difference can be marginal.
Summary
Both systems record video data and are very reliable. As with all types of technology it comes down to cost. NVR IP systems are certainly more expensive than their analog counterparts however if you are looking for a simple to use CCTV surveillance system to record and monitor your property an analog system will be fine for the task. Should you wish to have greater flexibility in camera options and use then it is certainly worth considering an NVR based IP system.