As you can see with a simple magnifying glass, the image produced by a lens is only ever sharp within a certain range of distance to the projection surface. With projectors, too, you generally have to focus the image when setting up the device or changing the throw distance. A projector with autofocus does this job completely automatically.
Autofocus is particularly useful for projectors that you often use in different locations, but also for ceiling-mounted devices that are awkward to reach. In addition, projectors with particularly bright lenses or long focal lengths, as well as Full HD projectors, place higher demands on focusing accuracy.
With a Full HD projector, this is due to the finer details it can display with its higher resolution. With lenses, on the other hand, the depth of field – the range in which the image appears sharp – decreases as the aperture gets larger and as the focal length increases.
