Camera is the most critical equipment, video monitoring and control system of its quality,
Fit and unfit quality directly affect the camera machine, therefore, the choice of camera is appropriate, is related to the quality system, and is related to the project cost.
Engineering design and construction personnel are often dealing with security monitoring camera;
Design personnel shall be calculated according to the object distance, and the size of the imaging lens focal length, construction personnel on-site commissioning, often is one part of the lens to adjust to the best state.
In the closed-circuit monitoring project, engineers often encounter lens matching problem;
To this end, we provide the following simple calculation formula of reference for selecting lens: formula 1: F = 2 wD/W formula: F = hD/H: F: lens focal length D: is the distance of the object lens W: is the object need to absorb the width of the H: is the height of the object needs to absorb W: H: the CCD target surface width of CCD target surface height: a closed-circuit monitoring project, with a third 'cameras, video cameras installed above the cashier 2 meters high, need to monitor system of the cashier counter situation of 2 meters wide, with how many mm lens?
According to the F = F = 4 wD/W formula calculation.
8 x2000/2000 = 4。
8 MMS choose 4.
8 mm lens.