To date, for security purposes, video surveillance is carried out by two types of cameras - digital and analog. Digital are followers of analog, but the latter do not lose their popularity to this day. This article is all about analog CCTV cameras.
How do they work?
The lens of the video camera captures the light flux and feeds it to the CCD matrix, converting it into an electrical signal and transmitting it along the cable to the receiving device. Analog video surveillance cameras differ from digital ones in that they do not convert the electrical signal into binary code, but transmit it to the recording mechanism in an unchanged form. This makes it possible to simplify the monitoring process and not process the signal on the computer. I must say that such a camera can be connected to a digital converter and receive a signal from several video cameras.
Devices of this type are able to transmit a picture on the network to anywhere in the world, and at once in several different places, displaying on several monitors simultaneously. For this, a multiplexer is used that branched the video signal into several monitors.
Characteristics of analog CCTV cameras:
- Permission . The low is 480 TVL, the average is 480-540 TVL, and the high is 540-700 TVL and higher. Analog CCTV cameras of high resolution make it possible to distinguish the faces of passers-by and the license plates of vehicles at a fairly large distance. Truth and DVR in this case it is required to install more powerful.
- Photosensitivity . A low 1.5 lux is used for shooting in bright daylight. The highest of 0.001 lux is capable of operating under any illumination.
- Characteristics of the lens . F2.8 covers a viewing angle of 90 degrees, and F 16 - no more than 5 degrees.
Very popular are analog CCTV cameras RVI, the latest models of which are of high resolution, capable of transmitting a signal for a distance of up to 500 meters, 20 times increasing the image and shooting even in the dark, with no light source at a distance of 100 m. In addition, the built-in IR-spotlight can be masked by the material and install the camera next to the road or highway. Analog cameras provide interoperability of individual mechanisms from different manufacturers, they are easy to assemble and customize. The device captures absolutely everything and has a low cost.