Fujifilm’s Linear and Nonlinear focus-ring settings change how a compatible lens’s electronic, focus-by-wire ring translates rotation into focus movement. Linear gives a fixed, repeatable relationship between how far you turn the ring and how much focus changes, regardless of speed, while Nonlinear varies that relationship with rotation speed, so a fast twist racks focus quickly and a slow turn allows fine adjustment. Only lenses and bodies that support this setting expose it, so check your specific menu and lens before planning a workflow around it, particularly one that relies on rehearsed focus marks.
Compare the Response Behavior
In concept, Linear response means a given amount of ring rotation always produces the same amount of focus travel, independent of how quickly or slowly you turn it, which is what makes it possible to learn and repeat a specific rotation for a specific focus change. In concept, Nonlinear response means the same amount of rotation can produce different amounts of focus travel depending on speed, so a quick, larger turn moves focus a longer distance for fast changes, while a slow, small turn allows finer control for precise adjustments.
These are the documented design intents rather than laboratory measurements, so when comparing the two on your own lens, test a fixed rotation at a slow, deliberate speed and again at a fast speed and observe the actual difference in focus travel, rather than assuming the described behavior applies identically to every lens and firmware combination.
Match the Intended Task
Video work that relies on rehearsed focus pulls, especially when marking the ring with tape or a follow-focus gear ring for repeatable hits between takes, generally benefits from Linear response, since a consistent rotation-to-distance relationship is what makes a rehearsed mark reliable take after take.
Stills shooting, where you often want to snap quickly from a near miss to an approximately correct distance and then fine-tune before the shutter, generally benefits from Nonlinear response, since the speed-sensitive behavior supports both a fast rough correction and fine adjustment from the same ring without switching settings.
Confirm After Setup Changes
Some bodies let you adjust how many degrees of rotation correspond to full focus travel in Linear mode, and this, along with the response mode itself, can be tied to firmware behavior or cleared by a settings reset. Re-confirm your chosen setting after any firmware update or menu reset rather than assuming it held.
- Re-test physical marks on the ring after any firmware update.
- Re-check the response mode after a full menu or settings reset.
- Confirm the setting again after swapping to a different lens body, since not all lenses support both modes.