CCTV Field of View is the width or height of a scene to be monitored by security camera. Field of View can be determined by the sensor format, the focal length of a lens, and the distance to the objects.
A simplified calculation for 1/4-inch CCTV lens can be made using the following formula:
W (horizontal width) = (distance) * 3.2 mm / (Lens Focal Length)
here 3.2 mm is the horizontal size of 1/4″ CCTV sensor and 4.8 mm for 1/3″ sensor.
It is very important to use the right lens for desired lens field of view, otherwise the images on security cameras will not be satisfactory. CCTV security camera lens with fixed focal length are less expensive and give smaller distortions but do not offer field of view choices.
To choose a proper lens the CCTV designer should consider all parameters. Do not use any online lens calculators because for proper lens selection you should consider both camera installation height and object height. Without all these parameters the calculation error can exceed 30%.
Proper calculation of CCTV Field of View and Lens focal length
Using our CCTV design software (CCTV Desing Tool or IP Video Design Tool) you can see how modification of any installation parameter can affect the result.
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