With the development of my country’s security surveillance industry, as a security technology, surveillance camera (closed-circuit television for short) is playing an increasingly important role in star hotels, foreign-related office buildings, banks, government agencies and other places. Including the current smart communities also use surveillance camera systems as an important means of security and property management. In order for surveillance camera technology to play a better role in intelligent buildings, how to choose the correct camera lens in every CCTV surveillance project is very important for economic indicators and technical performance.
Lens classification
According to the application of civil buildings, the types of surveillance camera lenses can be roughly divided into:
(1) Wide-angle lens: The angle of view is above 90 degrees, and is generally used in places with small visual distances and large viewing angles in elevator cars, halls, etc.;
(2) Standard lens: the angle of view is about 30 degrees, generally used in places such as walkways and the perimeter of the community;
(3) Telephoto lens: the angle of view is within 20 degrees, the focal length ranges from tens of millimeters to hundreds of millimeters, used for long-distance surveillance
(4) Zoom lens: The focal length range of the lens is variable, from wide-angle to telephoto, used in areas with a large depth of field and a wide range of angle of view;
(5) Pinhole lens: used for concealed monitoring.
When choosing a lens, the following five factors determine the lens standard:
(1) Monitor the size of the site;
(2) The size of the subject;
(3) Object distance;
(4) Focal length;
(5) CCD target surface size.
