Focus-by-wire design
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Focus-by-wire design

Hybrid AF systems tend to work best with lenses that use single, light focusing elements, since it reduces inertia to allow a highly-precise contrast detection check. This, along with the need to focus silently for video work, encourages the use of different focus motors than the ones used for DSLR lenses.

A knock-on effect of this is that the Nikkor Z lenses don't use the ring-type focus motors that Nikon has used for its high-end DSLR lenses. In turn this means designs with no physical connection between the focus ring and the focusing elements: an approach known as focus-by-wire.

Nikon uses this lack of mechanical connection by offering a speed-sensitive response: moving the focus a lot if you turn the ring quickly or in more subtle increments if you move it slowly. It'll be unfamiliar if you're used to DSLR lenses but it can allow fast and precise focus once you're used to it. Nikon also let you use the focus ring for other functions, if you prefer.

However, this isn't the only way focus-by-wire lenses can work, and there's nothing to stop Nikon adding a linear response mode that would be more like the way its existing lenses operate. This is particularly useful for videographers, since it makes it possible to plan-out a focus pull, knowing that a 30 degree turn of the focus ring will give drive the focus to the distance you expect.

It would also be possible for Nikon to let you reverse the lens rings' direction of operation, so that it focused like other brands' lenses. At present, Nikon isn't offering either of these options, but we're hoping they'll add them at some point in the future.