Optical lens do play a critical role within the conception of a surveillance system. Their primary objective is to reflect images from a scene and to put emphasis on the lightning in order to obtain a clear and defined image. Typically, the more light passes trough the lens, the better the quality. The selection of an appropriate lens is critical. It will affect the size, the shape and the clarity of an image. Factors like distance from the scene, focal length, required field of view, lightning and the size will affect the dimensions and clarity of the camera and that is why choosing the appropriate lens is necessary even if too often neglected by many installers with a lack of experience and knowledge in surveillance technologies. Field of View The field of view is produced by a specific lens and reflected by the actual image (width & height). If the field of view obtained is not the one desired, you may consider using a different one (angle, width, telephoto, etc.). to increment or decrement the field of view. Some tables are available to calculate the size of the image, the lens and the distance all combined to obtain de required field of view. There are two different types of lens, fixed or varifocal. The fixed lens possesses a fixed focus. The varifocal lens is adjustable. The focal length is simply the distance from the optical center of the lens to a focal point close to the back of the lens. This distance is written on the lens (in mm) et indicates the field of view produced by the lens.  Calculate the field of viewCalculate the Lens Format | 
Shopping Cart 
