|Frequently Asked Questions|
FAQ1 What are the differences between analogue and IP?
Normally analogue is compared with digital and then digital non-IP is compared with digital IP. So there is a gap of 2 generations. (a) Previously camera signals were generated in a physical quantity that is a measure of voltage. Modern camera signals were generated in a digital form based on computer binary digits. Binary digits are more precise than voltage measurements. (b) IP stands for Internet Protocol which is an open standard for data communication. Obviously complying with an open standard is better than not complying (which could be anything mysterious or even wrong). Effectively, IP video surveillance offers better camera images than analogue systems.
A megapixel is a unit element measurement of graphical display resolution equivalent to one million pixels (ref: 1,048,576 or 220 to be exact). A pixel is a minute area of illumination on a display screen which an image is composed of.
The camera form factor describes the body type enclosing the camera. The different types of camera bodies are suited for different locations and surveillance requirements. The camera bodies can range from bullet, dome, or box types down to fisheye and covert types.
PTZ cameras have additional mechanical parts that provide the capability to pan, tilt and zoom (PTZ) the camera lens allowing the monitoring of different areas that would otherwise require multiple fixed cameras.
A Network Video Recorder (NVR) is a normally a computer-based camera video processing and recording system. It includes a software program to receive pure digital signals from IP cameras and to store the signals as video clips or frames in a storage device. NVR is based on Internet Protocol for data communication. In contrast, DVR receives analogue signals over coaxial connections from analogue cameras. NVR is modern technology and DVR is phased-out technology.
The camera footage is saved in a storage medium in the NVR such as a Hard Disk Drive or Solid Disk Drive which can be replayed at any time. The replaying length and amount of video footage stored depends on the storage capacity of the device.