Today I went on a hardware store hunt. What for? To find parts to build my own do-it-yourself follow focus. What is a follow focus? It’s a piece of equipment that allows you to mark off different focus positions for quick and easy focus pulls.

A professional follow focus cost over $1,300. While they are very well made and easy to use, they do have some drawbacks. First, they’re not easily adjustable, especially when out in the field. You have to purchase a different set of rings and gears to fit different types of lenses, which also makes an already expensive piece of equipment more expensive. They’re also bulky, requiring a rail system to clamp on to. Fortunately, for those on a budget, there’s an inexpensive DIY alternative. It’s small, adjustable, and will only cost you $10.

To build it you’ll need these items:

  • A hose clamp
  • A 3 inch or longer threaded bolt and nut
  • A roll of foam tape weatherstripping
  • A paper clip
  • A few elastic bands

First, you’ll want to take your hose clamp and adjust it so it’s circumference is slightly bigger than your lens.
Then, mark off a point on the hose clamp for the bolt and drill a hole big enough to put it through. Insert the bolt into the hole, with the head on the inside of the clamp. Use the nut to secure it in place.
Take your foam tape and line the inside of the hose clamp, making sure you cover the head of the bolt. You don’t want to damage your lens, now do you? 😛
Makes sure the whole unit will fit snugly on your lens’s focus ring. Don’t force it on too tight. You’ll end up damaging the follow focus, or worse, the lens.
Finally, take your paper clip and straighten it. Wrap one end of it around the bottom of the bolt, leaving the other end sticking out. This is the needle you’ll use to mark off your focus positions.

In the end, you should end up with something like this:

Now, to mark off your focus positions, put an elastic band around the lens. For most lenses, a size 64 elastic should fit. Find your focus and mark off on the elastic where the paper clip lands. For more accurate marking, bend the paper clip so it hovers as close to the rubber band as possible. Then find and mark off your next focus position(s). Congratulations, you have a fully functioning follow focus, and you saved $1,290! 😀