Printed Focus Control For Pro Style Cinematography

June 7, 2025 by Jenny List 14 Comments

When you watch a movie and see those perfect focus switches or zooms, the chances are you’re not seeing the result of the cameraman or focus operator manually moving the lens controls. Instead, they will have been planned and programmed in advance and executed by a motor. If you take a close look at many lenses you’ll see a ring that’s more than just extra knurling, it’s a gear wheel for this purpose. Want to experiment with this technique without buying professional grade accessories? [l0u0k0e] has you covered with a 3D printable focus zoom motor accessory.

The motor behind it all is a geared stepper motor, and there are a set of printed parts to complete the model. It’s recommended to use PETG, and nylon for the gears, but it would work in PLA with a shorter life. It’s designed to work with the standard 15 mm tube you’ll find on many camera rigs, and while you can write your own Arduino sketches to control it if you wish, we’re given instructions for hooking it up to existing focus drivers. The model is on Printables, should you wish to try.

This is by no means the first focus puller we’ve seen, in fact you can even use LEGO.

Kinect And Raspberry Pi Add Focus Pulling To DSLR

August 27, 2016 by Dan Maloney 19 Comments

Prosumer DSLRs have been a boon to the democratization of digital media. Gear that once commanded professional prices is now available to those on more modest budgets. Not only has this unleashed a torrent of online content, it has also started a wave of camera hacks and accessories, like this automatic focus puller based on a Kinect and a Raspberry Pi.

For [Tom Piessens], the Canon EOS 5D has been a solid platform but suffers from a problem. The narrow depth of field possible with DSLRs makes it difficult to maintain focus on subjects that are moving relative to the camera, making follow-focus scenes like this classic hard to reproduce. Aiming for a better system than the stock autofocus, [Tom] grafted a Kinect sensor and a stepper motor actuator to a Raspberry Pi, and used the Kinect’s depth map to drive the focus ring. Parts are laser-cut, including a nice enclosure for the Pi and display that makes the whole thing reasonably portable. The video below shows the focus remaining locked on a selected region of interest. It seems like movement along only one axis is allowed; we’d love to see this system expanded to follow a designated object no matter where it moves in the frame.

If you’re in need of a follow-focus rig but don’t have a geared lens, check out these 3D-printed lens gears. They’d be a great complement to this backwoods focus-puller.

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Hillbilly Lego Focus Puller

January 1, 2016 by Elliot Williams 10 Comments

There’s almost nothing you can’t build with the right set of Lego parts. [Rigjob] built up a Lego-based wireless remote follow-focus system that’ll give professional systems a run for their money.

Now [Rigjob] self-identifies as a hillbilly, but he’s not just a redneck with a camera. He’s set up the Lego controller to remember minimum and maximum focus positions as well as mark points along the way. The controller simply won’t turn the lens outside of the focus range, and an interactive graph shows you where you are within the range. For a focus wheel, he uses (drum-roll please!) a Lego off-road wheel. It looks really comfortable, usable, and actually quite professional.

There’s a lot of tech in the Lego controller and motors that make this “simple” hack simple. Under the hood, there’s a Bluetooth connection, a geared stepper motor with a position sensor, a communication protocol, and a whole ton of programming in the Lego controller that makes it all drag-and-drop programmable. But to a long-bearded hillbilly cameraman, it all looks like child’s play. And that’s the hallmark of good design. Kudos, Lego.

If you can’t get enough Lego camera tech, check out this DIY slit-scan stargate rig, or (what else?) a Lego 3D chocolate printer.

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3D Printed Lens Gears For Pro-grade Focus Pulling

November 17, 2015 by Dan Maloney 29 Comments

Key Grip, Gaffer, Best Boy – any of us who’ve sat through every last minute of a Marvel movie to get to the post-credits scene – mmm, schawarma! – have seen the obscure titles of folks involved in movie making. But “Focus Puller”? How hard can it be to focus a camera?

Turns out there’s a lot to the job, and in a many cases it makes sense to mechanize the task. Pro cinematic cameras have geared rings for just that reason, and now your DSLR lens can have them too with customized, 3D printed follow-focus gears.

Unwilling to permanently modify his DSLR camera lens and dissatisfied with after-market lens gearing solutions, [Jaymis Loveday] learned enough OpenSCAD to generate gears from 50mm to 100mm in diameter in 0.5mm increments for a snug friction fit. Teamed up with commercially available focus pulling equipment, these lens gears should really help [Jaymis] get professional results from consumer lenses.

Unfortunately, [Jaymis] doesn’t include any video of the gears in action, but the demo footage shown below presumably has some shots that were enabled by his custom gears. And even if it doesn’t, there are some really cool shots in it worth watching.

And for the budding cinematographers out there without access to a 3D printer, there’s always this hardware store solution to focus pulling.

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