中文字幕日本在线观看_91久久久久_国产精品欧美综合_国产精品s色_福利久久久_国产二区视频_欧美日韩大片

Monitoring camera viewing Angle table, check Chinese version.

Surveillance cameras use place and point of view
1, wide-angle lens: the perspective above 90 degrees, is generally used in elevator, hall and other places of small stadia big Angle of view in the 2.8 MM to 2.5 MM
2, view above 60 degrees, for 5 * 5 meters place 3.6 MM to 4 MM
Camera in more than 50 degrees, 3, 6 mm for 8 to 10 meters places
4, the perspective above 40 degrees, for 10 to 18 meters place 8 mm
5, perspective above 30 degrees, for 20 to 30 meters place 12 mm to 16 mm
6, perspective above 20 degrees, 25 mm for 30 to 50 meters places
7, the telephoto lens: perspective within 20 degrees, the focal length range from a few millimeters to hundreds of mm, used for remote surveillance;
8, zoom lens, lens focal length of the variable range from wide Angle to telephoto, used for large depth of field, perspective is wide area;
9, pinhole lens: used for covert surveillance.
The lens is smaller, the greater the area of monitoring, and the image object is relatively small.The smaller the lens, the greater the monitoring area (narrow), and a relatively large image object.
Calculation method of 1/3 "CCD camera can see as far as how many meters?
3.6 MM, 6 MM, 8 MM, 12 MM, 16 MM, 25 MM how many meters multiplied by 2.4 is the farthest distance
Can simple calculation method: visual range present 2 is equivalent to the lens, and reference point of view
Cif 640 KB/s (300 m per hour/day 7 g
D1 2084 KB/s (900 m per hour / 22 g every day