The D/Focus Systems D/Focus V3 Follow Focus is among the most affordable follow focus systems out there and features just about every function that a follow focus could come with. It can be used with cinema lenses and optionally with still lenses, but as it comes, it's designed for use with specifically cinema lenses. V3's gear wheel has a 0.8 pitch, "pitch" referring to the spacing between the teeth of the wheel. Cinema lenses natively have a 0.8 pitch on their focusing rings, and thus V3 is natively compatible with them. Those of you (likely all of you) who have or who plan to use still lenses, the kind that often come with a DSLR, the kind that don't have teeth on their focusing rings, (or at least teeth not sharp enough to create a 0.8 pitch), simply need to get a separately-sold and very affordable D/Gear from D/Focus, and then you'll be able to use V3 with both cinema lenses and still lenses. D/Gear wraps around a still lens to make it compatible with 0.8 gear wheels.
Now to all the functions. V3 is a rod-mount follow focus. It mounts and tightens onto two standard-size 15mm rods, which as a pair are part of most every camera rig, as the foundation of that rig, as the base. Per a component called a "gear plate" being reversible in the V3, you can mount V3 on either side of the rig, to position it on either side of a camera. Mounting on either side means you can use the follow focus left handed or right handed. Once mounted, V3 is a lens-adjustable follow focus -- the top part slides left or right to line up to a lens, and thus V3 supports different lens diameters, pretty-much all the common ones.
A quality benefit V3 offers is little-to-no backlash. V3's gearbox tension is adjustable to reduce backlash to near zero. What this means is that you won't experience gaps, space, looseness, between the teeth of the gear wheel and the lens, and hence you'll have more fluid focus pulls.
V3 comes outfitted with a 3D marking disk for marking focus stops. And it has a standard size port on its focusing wheel for optional whips and cranks to be attached into. These attach to let an assistant pull focus for you from a foot or more away.
A Most Affordable Full-Function Follow Focus
Mounts 15mm rods on either the left or right side of the camera
Adjusts to different lens diameters, and thus works with most all lenses
Compatible with cinema lenses and per the addition of D/Gear with still lenses