Interchangeable lenses are used with box cameras and some specialist models, where the field of view must match the scene exactly. Hikvision offers fixed, varifocal and motorised zoom lenses for different sensor sizes and working distances. These range from wide-angle lenses for entrances and lobbies to long focal lengths that pick out detail at a gate or along a perimeter. The lens has to match the sensor size and resolution, or the corners of the image will blur.
Choosing the focal length is a calculation, not a guess. It depends on how wide the scene is, how far away the target is and whether you need to detect, recognise or identify a person or vehicle. Transit works this out at the design stage for each camera, so the image gives the detail needed. On site, we focus and set up each lens, check the result in day and night conditions and adjust where needed. See our CCTV systems page or the wider Hikvision range. Contact Transit with your camera model and scene for a lens recommendation and price.