Fujifilm introduced a new feature called ‘AF-C Custom Settings’ in the AF/MF Setting page of the X-T2’s menu and it’s designed to help you tailor the response of the autofocus system to suit specific subjects or shooting conditions. It’s proved a popular addition, and has subsequently been included in the X-T20’s feature set.
Both cameras have 5 preset AF-C Custom Settings with names that give a clue to their purpose; Set 1 Multipurpose, Set 2 Ignore Obstacles & Continue to Track Subject, Set 3 For Accelerating/Decelerating Subject, Set 4 for Suddenly Appearing Subject and Set 5 For Erratically Moving & Accel/Decel. Subject.
Each of these options sets specific settings for three focus tracking parameters, Tracking Sensitivity, Speed Tracking Sensitivity and Zone Area Switching. In addition to the preset options, the X-T2 has ‘Set 6 Custom’, which allows you to specify the values that you want to use.
Tracking Sensitivity determines how long the camera waits before adjusting focus when another object enters the focus area. The higher the number, the longer the camera will wait. A high value could be useful when shooting a team sport when other players come between you and the subject or when other objects are likely to get in the way when panning with a subject.
Speed Tracking Sensitivity
Speed Tracking Sensitivity controls how sensitive the tracking system is to changes in the speed of the subject. The higher the value, the more the camera will attempt to respond to sudden changes in speed, however, the camera will have more trouble than usual with low contrast or very reflective subjects. A high value is useful for subjects such as wildlife that can move and change speed quickly.
Zone Area Switching
Zone Area Switching only takes effect when Zone AF mode is selected and it sets the focus area that is given priority within the selected zone. There are three settings; Center, Auto and Front. When Center is selected the camera prioritises objects in the centre of the zone while in Front it gives priority to the subject nearest to the camera. Meanwhile when Auto is selected, the camera locks focus on the subject at the centre of the zone but switches focus area as necessary to track it. Auto makes a good general purpose setting, but it’s worth experimenting with the others.
Using the AF-C Custom Settings
As mentioned earlier, the AF-C Custom Settings are selected via the AF/MF Setting page of the menu. Before you make a selection it’s a good idea to give a little thought to your subject and surroundings. In many instances Set 1 Multipurpose will serve you well, but you may get a higher hit rate in some situations with the others.
If you’re panning in an area with trees or street lamps, for example, Set 2 Ignore Obstacles & Continue to Track Subject could be a good choice that keeps the camera focused on your subject.
Set 3 For Accelerating/Decelerating Subject is a good choice for motorsports or races where the subject is likely to slow into a corner (for example) before accelerating away.
Set 4 For Suddenly Appearing Subject is useful when you don’t know when or where a subject will appear - perhaps if you’re waiting below the brow of the hill or around the bend in a race.
Set 5 For Erratically Moving & Accel/Decel. Subject makes a good choice for wildlife, especially birds in flight as they move randomly and with varying speed.