Advanced Focus Assistance System (Af System) - FujiFilm UA107x8.4BESM-T35K Operating Manual

８. Advanced focus Assistance System (AF SYSTEM)
The Advanced Focus Assistance System (AF System) is a new autofocus system for 4K-TV cameras.
In the 4K-TV system, even though the blur of the subject is not detected on the viewfinder of the camera, it can be
recognized if it is displayed on a larger display. For that subject, the AF System automatically find the best focus
actively. Since the AF System works actively, the best focus is continuously maintained even if the subject is moving.
Note. In the case the blur amount of the subject in the AF frame is relatively large, the AF System will not find the
best focus.
In that case, manually move the focus to a position nearer the best focus; or temporarily move the zoom to
the side of wider-angle so that the image of the subject is sharpened, and then resume the former zoom
position.
If the amount of blur is decreased, the AF System automatically works to find the best focus.
8.1 About Advanced focus Assistance System
8.1.1 Features of AF-System
・ In the AF System, at first the camera operator performes the focusing operation. After that the AF System
automatically assists the operator to find the best focus.
・ The focus finding movement is not shown on the display.
・ A subject moving along the optical path can be kept in
best focus as well as one that is being zoomed in or out.
・ If the camera supports the AF system, this system displays
the AF frame on the viewfinder and allows you to specify
the position where you want to focus.
Note. If the camera does not support the AF system, the AF point
will not be displayed. In this case, the AF system operates to
focus on a rectangular area in the center of the screen (50%
horizontally and 80% vertically) relative to the screen size.
8 .1.2 Difficulty in acquiring and maintaining focus
The AF system has difficulty in acquiring and maintaining focus with subjects (or sisuation) as listed below.
・ Low contrast subject. （a blue sky, a monochromatic plane, etc.）
・ Rain, snow, or heat haze.
・ High illumination spot in AF frame.
・ The object which distance differ from the subject is in the AF frame.
・ The subject in a night view or a dark place.
・ The subject is moving quickly.
・ Subject of a repeating pattern.
8.1.3 AF System functioning range
・ Excluding near wide end.
・ Excluding narrow aperture side.
However, the F value at which AF functions decreases as the distance from the center of the AF frame
increases.
AF frame size and position
AF frame fixed at center
- 10 -
can be changed