AFZ / Varifocal lens for Machine Vision
![Motorized focus lens C-mount 20MP 50MM F2.8 for max sensorsize 1.1" with controller](http://va-imaging.com/cdn/shop/files/AFZ-Varifocal_lens-example_controller.png?v=1739009179&width=500 "Motorized focus lens C-mount 20MP 50MM F2.8 for max sensorsize 1.1" with controller")
Features of a Varifocal lens
A varifocal lens is a manually adjustable zoom lens that allows you to control the focal length. The opening angle becomes larger by zooming out and smaller by zooming in. a result, you can focus the lens at a range of distances from the object, allowing the possibility of multiple working distances. Therefor eliminating the need to switch a lens at each specific working distance. During installation you optimize the focal length (zoom settings) and during operation, you keep the settings fixed.
Features of an Auto Focus Zoom lens
Auto Focus Zoom (AFZ) lenses originate from the security and consumer market. With this zoom lens, the camera automatically operates the focus. As a result, the image is always in focus. Additionally, the zoom lens has the option of being controlled electronically. Even this is called an Auto Focus Zoom lens, however in this case the focus and zoom should be controlled remotely and not automatically by default.
AFZ lenses are not commonly used in machine vision, as manual focus control is often preferred for precise focus placement. More often, c-mount lenses with a fixed focuses are used. For applications where controlling the zoom and focus remotely is required, the AFZ lens offers a great solution.
Differences between AFZ lenses and Varifocal lenses
In general, zoom lenses are often called varifocal lenses. However, just like the AFZ lens, the varifocal lens is a type of zoom lens. Both are zoom lenses, but these are the main differences: machine vision applications.
AFZ lenses have autofocus, where Varifocal lenses are manually focused.
AFZ lenses can be automatically controlled, where Varifocal lenses require manual control.
AFZ lenses are often used in applications such as security or as a consumer camera, where varifocal lenses offer a more industrial and accurate solution for machine vision applications.
In conclusion, varifocal lenses offer the most suitable solution for situations where precise control over the image's focus is required. AFZ lenses offer a great solution for applications that require consistently in focus images.
