What indicators should I pay attention to when choosing a camera?

1. Is the camera chip CCD or CMOS? At present, the CCD chip is used in most cases of surveillance cameras;
2. The size of the CCD chip: At present, there are mainly 1 inch, 2/3 inch, 1/2 inch, 1/3 inch, and 1/4 inch, of which 1/3 inch and 1/4 inch CCD chips are mostly The larger the chip, the better the image quality and the more expensive the price;
3. The pixels of the CCD camera: the larger the pixels, the clearer the image;
4. Horizontal resolution of CCD: The resolution is expressed by TV lines (referred to as tv lines for short). The typical resolution of a color camera is between 320 and 500 TV lines, mainly with 330 lines, 380 lines, 420 lines, 460 lines, 500 lines and other different grades;
5. Lens: Calculate the focal length of the lens according to the object distance and imaging size, select the appropriate focal length lens such as standard lens, long focal length lens, short focal length lens, and also need to consider that the imaging size of the lens should be consistent with the size of the camera CCD target surface There are also factors such as lens resolution and aperture;
6. Minimum illumination: Also called sensitivity, it is the sensitivity of the CCD to ambient light, or the darkest light required by the CCD for normal imaging. The unit of illuminance is LUX. The smaller the value, the smaller the light required and the more sensitive the camera. Moonlight-level and starlight-level high-sensitivity cameras can work in very dark conditions, 1 ~ 3lux is general illumination.

Moonlight type: the illuminance required for normal work is about 0.1lux;
Starlight type: Illumination required for normal work is less than 0.01lux;
Infrared type: Illuminated by infrared lamp, it can also image (black and white) when there is no light.

7. Signal to noise ratio: The typical value is 48db. 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. Other factors: such as automatic gain and white balance.