A lens gathers reflected light from the scene and focusesit onto the cam picture sensor. This is practically equivalent to thelens of the human eye centering a scene onto the retinaat the once more of the eye. As in the human eye,the cam lens rearranges the scene picture on the imagesensor, yet the eye and the cam hardware compensate(invert the picture) to see an upright scene. The retinaof the human eye contrasts from any CCTV lens in that itfocuses a sharp picture just in the focal 10% of its total160 FOV. All vision outside the focal centered scene isout of centering.
This focal imaging piece of the human eyecan be portrayed as a medium FL lens: 16–25 mm. Inprinciple, Figure above speaks to the capacity of any lensin a feature system.many diverse lens sorts are utilized for feature surveillanceand security applications. They run from the simplestffl manual-iris lenses to the more unpredictable variable-focallength(vari-central) and zoom lenses, with a programmed irisbeing a choice for all types.in expansion, pinhole lenses are accessible for undercover applications,split-picture lenses for survey different scenes onone cam, right-plot lenses for review a scene perpendicularto the cam hub, and unbending or adaptable fiber-opticlenses for review through thick dividers, under entryways, and so fort