A follow focus is a mechanism used to adjust the focus ring on a lens without having to directly touch the lens barrel.
While very useful, follow focus units are also very expensive. The reason for this is because they have to be precision milled to incredible accuracy or else shots could be “soft” as a result.
Unfortunately, you may be in a situation on a low/no-budget film where production won’t rent a follow focus or you’re a one-man-band filmmaker who can’t afford one.
Luckily there are some easy techniques to rig up a follow focus on the cheap, most for under $10.00.
Most of these DIY follow focus units will be more usable on still or ENG lenses. This is because those lenses are not geared like Cine-style lenses and a lot of these solutions depend on the sticky rubber of the still lens’ focus ring. Still, this could be a jumping off point if you’re trying to make a DIY cine-style follow focus
While searching the web and many forums, I came across a variety of techniques, but most of the methods fell into these five types:
1. Hose Clamps
The hose clamp method is fairly simple: You take a hose clamp roughly the size of the lens barrel, drill a hole into it, then use a bolt to attach a knob/handle to the clamp. Some other methods have used a rubber band underneath the clamp to soften it against the lens and help it stick better.
Andre Desrochers took this method a step further in his DIY follow focus by finding a way to add marking capabilities. Check out Vimeo for Andre’s tutorial on making this design:
Overall, this is one of the simplest and easiest methods out there. The design is not only cheap – $5 by most estimations – but easy to accomplish in a few steps.
The only problem is that many of the designs have a short stick or knob. To make this truly practical in a setting in which there is an AC and an operator, one would need a longer stick allowing the AC or focus puller to stand behind or near the operator.
The other benefit to using a hose clamp is that if you get the kind of clamp with the notches you could probably mount it on a cinema style lens by feeding the gears through the notches.
Here are some other pictures of the hose clamp method:
2. Roller Skate Wheels
Prior to writing this post, I hadn’t even been aware of a solution like this — it’s quite ingenious. Though the designs differ greatly, the idea is to use simple inline skate wheels ($3 for the cheapest kind, I found online) as an alternative to geared lenses and follow focus mechanisms.
And here is the diagram for how to make the unit itself:
This technique seems to be more intense on the engineering side, though the trade off is what appears to be a stickier, and thus more accurate, DIY follow focus.
I like the idea of the skate wheel, though it wouldn’t work to the same effect on Cinema style lenses – I’m not sure how the wheels would grip against gears as opposed to rubber.
3. Jar Openers
This method is suggested by camera assistant David Elkins in his book, “The Camera Assistant’s Manual.”
The device is self-explanatory and Elkins also suggests it can be used to do zoom moves if your follow focus is busy, well, focusing.
I’ve heard of people using jar openers before, but unfortunately I have found them hard to come by. An internet search turns up nothing and when I first started AC-ing, I looked for something like this at as many home improvement and home goods stores I could find, but came up empty handed.
4. Zip Ties
The cheapest solution I found was to pull a few zip ties over the lens. In my personal experience, this is a quick and dirty way to make a follow focus and works wonderfully.
Though the zip tie itself doesn’t protrude much unless you buy big ones (or use two together) it is easy to whip together on set if you’re in a bind. It also doesn’t work very well on lenses that are geared.
Lastly, using a thin strip of gaff tape underneath the zip tie helps it to stick better and make for smoother focus pulls.
5. Plastic Tubing
Here’s another very inexpensive focus puller made of plastic tubing with a nut inside the tube and a screw through the tube into the nut. Less than a buck and doesn’t do any harm to the lens. It can be quickly removed when necessary. Works great for me. It took all of five minutes to make. It could be refined to look better but it does the job.
The instructions are a little vague and I’m still not exactly sure what’s going on in the pictures, but it seems to be able to work.
If only the protruding tube was extended a bit longer it would make the technique more practical. The upside to this, that I can see, is being able to extend the protrusion with simple tube attachments allowing you to make different sized whips.
Be Resourceful with Your Follow Focus Solution
Whether for a cash-strapped production or a backyard DP, these are very inventive and great ideas for making your own follow focus. Just make sure that you’re familiar with the art of pulling focus and get some marks while you’re at it.
It also helps if you’re incredibly resourceful when building these follow focus devices. Don’t stick to the plans outlined above if you have an idea to make it better or more suited to your working style. It’s all about customization.