A camera lens in which the focus is not fixed and that can be adjusted either manually or automatically.
a lens which must be refocused whenever you change its focal length
A type of lens that enables a manual selection between two focal lengths, to give the desired picture view. A good option for customers, who are unsure of angle or distance, as it saves having to try multiple lenses.
A projection lens containing movable elements to permit focusing by varying the focal length. (Not a zoom lens.)
Is one type of lens found on some cameras. This lens allows the user / installer to manually adjust the camera's field of view. Varifocal lenses can therefore be changed to provide wider viewing angles or narrower telephoto viewing angles. Because of their adjustability, varifocal lenses are great when a camera will serve more than one purpose or to ensure proper focus without first determining an exact fixed lens focal length. Varifocal lenses are also typically referred to as zoom lenses. Video Input Type refers to the type of video a device will accept for display, recording, etc. AutomatedSurveillance.com equipment (just like the majority of consumer video equipment most clients have at home) is made for compatibility with composite video. For use with S-Video, RGB component video, VGA, or other specialized / digital video formats, an adapter or converter may be required.
A lens that can be manually adjusted for the desired magnification and field of view.
Optical assembly containing several movable elements to permit changing the effective focal length (EFL). Unlike a zoom lens a varifocal lens requires refocusing with each change.
A projection lens containing movable elements to permit focusing of the image. (Not a zoom)
A varifocal lens provides a wide range of focal lengths, as opposed to a lens with a fixed focal length, which only provides one.
See Zoom Lens. Usually not motorized (manual).
Is a type of manual zoom lens with a small zoom ratio (ranging between 4mm to 12mm depending on brand). It is used when the focal length of the lens needs to be fine tuned to meet the requirements of the actual scene.
A cctv camera lens whose focal length / viewing angle can be manually adjusted to suit the camera view required. Typical Vari Focal lens lengths are: 2.5mm-10mm, 3.5mm-8mm, 5mm-50mm
A projector lens that has three focal elements contained in a single assembly.
A camera lens in which the focus is not fixed, it can be manually or automatically adjusted.