So, you want to get a video security system and even decided how many cameras you nee. The next thing on your ‘to-do list’ is to decide what resolution you need.
Resolution for both analogue cameras and network IP cameras is determined by pixels. Simply put, it is the size of the image that you record. If it is too small – you won’t be able to use the footage for identification purposes. If it is too big, you may be unnecessarily overpaying for the camera and your recorder’s hard drive. So in the ideal world – you would want to get just the right camera for the job at hand.
In analogue cameras, an image consists of horizontal and vertical lines which used to be capped at 720 x 576 pixels (PAL - Phase Alternating Line standard). Since 2015 you can get a high definition analogue format enabled support for 720p (1280 x 720 pixels) and 1080p (1920 x 1080 pixels) HD resolutions.
The resolution of an IP (network) camera works in the pretty much same way, except that it uses an image sensor to capture images which are then transmitted as chunks of data over a network cable or Wi-fi in a compressed format. An IP camera can produce an image containing million or more pixels that allow a user to see more details or view a larger area of a scene. IP cameras typically have a range of 2MP – 8MP (4K) or even 12MP capabilities.
NB! More does not always mean better! We often come across a phenomenon that we call ‘pixel-mania’ where a client wants to get a 4k camera no matter what ‘just because it sounds cool’. That isn’t necessarily the right approach, the choice of a camera should be dictated by the purpose you intend to use it for. It is true that a 4k resolution camera will give you a great quality picture with a lot of zooming potential…that is, if it has sufficient ambient light. But its quality will not be much better than a 2MP starlight camera in low light conditions, you may end up paying much more for very little added value.
Resolution on its own isn't the whole story, naturally. Frame rates, lens types, Infrared (IR) night vision and on-board software, all make a difference to the quality of the captured image.