What are the main parameters of the camera?

What are the main parameters of the camera are the key points that this article introduces for everyone:

In the closed-circuit monitoring system, the camera is also called the camera. Strictly speaking, the camera is the general name of the camera and the lens.

The core of the camera is CCD. At present, there is no CCD and production capacity in China, mainly concentrated in Japan and South Korea. Due to the different grades of CCD in the production process and the different ways of obtaining by the manufacturer, the acquisition effect of CCD is different. A simple The detection method is to energize the camera, not to connect the lens, cover the lens interface with your hand, to see if the image has bright spots, the snow is not big, then attach the lens, point the camera at a brightly colored object, and check the color of the monitor. Whether there is color cast, whether the image is distorted, whether the color and gray scale are smooth.

Since the core component of the camera is a CCD, its main parameters are mostly related to the CCD. The main parameters of the camera are listed below:

(1) CCD size, which is the camera target surface. Originally more than 1/2 inch, now 1/3 inch has become popular, 1/4 inch and 1/5 inch have also been commercialized.

(2) CCD pixels, which are the main performance indicators of CCD, determine the clarity of the displayed image. The higher the resolution, the better the image details. The CCD is composed of area array photosensitive elements, each of which is called a pixel. The more pixels, the clearer the image. Most of the market is currently delimited by 250,000 and 380,000 pixels, and more than 380,000 pixels are high-definition cameras.

(3) Horizontal resolution. The typical resolution of color cameras is between 320 and 500 TV lines, mainly 330 lines, 380 lines, 420 lines, 460 lines, 500 lines and other different grades. The resolution is represented by a TV line (referred to as the line TV LINES), which has a resolution between 33 and 500 lines. The resolution is related to the CCD and the lens, and is also directly related to the bandwidth of the camera circuit channel. The usual rule is that the bandwidth of 1 MHz corresponds to a resolution of 80 lines. The wider the band, the clearer the image and the larger the line value.

(4) Minimum illumination, also known as sensitivity. It is the sensitivity of the CCD to ambient light, or the darkest light required for normal CCD imaging. The unit of illuminance is lux. The smaller the value, the less light is needed and the more sensitive the camera. Moonlight and starlight level high-sensitivity cameras can work in very dark conditions, 2~3lux is general illumination.

(5) Scanning system. There are PAL and NTSC systems.

(6) Camera power supply. The AC has 220V, 110V, 24V, and the DC is 12V or 9V.

(7) Signal to noise ratio. The typical value is 46db. If it is 50db, the image has a small amount of noise, but the image quality is good. If it is 60db, the image quality is excellent and no noise occurs.

(8) Video output. Mostly 1Vp-p, 75Ω, all use BNC connectors.

(9) Lens mounting method. There are C and CS modes, the difference between the two is that the sensing distance is different.