How to Replace a Follow Focus Gear Ring Belt

Quick answer

To replace a follow focus gear ring belt, remove the old belt from the lens barrel, clean the surface, then wrap the new replacement belt around the lens and secure it with the adjustable sliding mechanism.

Step-by-step replacement guide

1. Remove the old gear ring belt: Slide the old belt off the lens barrel. If it's stuck, gently work it off with your fingers. Do not use sharp tools that could scratch the lens body. Check if the old belt has stretched unevenly — that can indicate a misaligned follow focus unit.
2. Clean the lens barrel surface: Wipe the area where the belt sits with a dry microfiber cloth to remove dust, oil, or debris. A clean surface helps the new belt grip evenly. Avoid alcohol or solvents near lens markings or painted surfaces.
3. Open the sliding mechanism on the new belt: Locate the adjustable slider on the Fotodiox replacement belt. Slide it open to its widest setting so the belt can fit around the lens barrel easily. Do not force the slider — it should move smoothly. If it's stiff, check for debris in the track.
4. Wrap the belt around the lens: Place the belt around the lens barrel at the desired position, usually near the focus ring. Make sure the gear teeth face outward toward the follow focus motor. The belt should sit flat and not twist. A twisted belt causes uneven gear engagement and noise.
5. Tighten the sliding mechanism: Slide the mechanism closed until the belt fits snugly around the lens. It should be tight enough not to slip but not so tight that it restricts the focus ring's rotation. If the belt is too loose, it will slip during focus pulls. If too tight, it may add drag to the lens focus ring.
6. Test the follow focus operation: Attach the follow focus unit and turn the knob through the full focus range. The belt should track smoothly without skipping or binding. Listen for clicking or grinding sounds — these indicate the belt teeth are not meshing correctly with the follow focus gear.

Product facts

• Replacement Gear Ring Belt for Follow Focus F1 for DV HDV DSLR - Pro Geared Focus Drive: Adjustable sliding mechanism to fit a large range of lens diameters, including video camera lenses. Geared tooth pitch 0.8 Mod 32, approximately 141 teeth, 11-½" long. Made of soft rubber for ample friction and precise gear engagement. This universal design means one belt can replace worn rings on multiple lenses, saving you from buying a different belt for each lens diameter.