Zacuto

Follow Focus Basics-Staying Focused

A follow focus is a focus control device used for shooting film or video.  The act of changing focus is called a focus pull or rack focus. A follow focus is not strictly necessary when shooting, but having one on your camera allows the operator to be more efficient and precise. The follow focus is usually operated by a focus puller or the 1st assistant camera (1st AC), but some camera operators prefer to pull their own focus.

There are many different follow focuses on the market today.  Some of the most popular brands are ARRI, Chrosziel and Zacuto.  Zacuto’s Z-Focus series has a follow focus for any type of camera set-up.  Unlike most other follow focuses, the Zacuto Z-Focus can be quickly switched to the “dumb side” (assistant side) which gets you out of the operator’s way without having to remove other pieces of the camera rig.  This can save valuable time on a film set.  The Studio Flippable Z-Focus is also available for 19mm studio rod camera setups.

A follow focus works through a set of gears that are attached to teeth on the focus ring of your camera lens.  The follow focus gears feed to a wheel which, when turned by a focus puller, will spin the teeth and thus the lens gear that focuses the image.

There are a few different pitch sizes when it comes to follow focus and lens gear teeth.  Pitch size refers to the length of and distance between each tooth on a gear.  The standard pitch size for film cameras is .8, but you will often find camera lenses with .5 or .6 pitch teeth.   The Zacuto Z-Focus can be equipped to work with .8, .6 or .5 pitch lenses.  If the teeth on your lens do not match the teeth on your follow focus, you will need to fasten a Zacuto Zipgear lens gear to your lens to pull focus.  Unless you are using a cinema lens with a .8 pitch already on it or a Canon or Fujinon broadcast lens, which is .5 or .6 pitch, you will almost always need a Zipgear.  Most lenses used with the Canon 5D Mark II or Canon 7D will require Zipgears.  With new cameras like the Panasonic AG-AF100, Sony F3 or Sony FS100, you may or may not need Zipgears depending on what lenses you are using.

The Zacuto Z-Crank

If you are not using a follow focus, the camera operator will have to turn the focus ring on the lens by hand.  This practice is quite common but it will sometimes place the camera operator’s hand in an awkward position.  Turning the focus ring beyond a certain distance (like 360 degrees) by hand is impossible.  A large rack focus is difficult to achieve even with a follow focus, so you may also need a speed crank or Z-Crank to achieve your focus pull.  A speed crank is an L-shaped metal rod that can be attached in the provided standard square mounting hole at the center of the follow focus wheel.  With a speed crank, the hand only has to spin the rod, which in turn spins the follow focus wheel.  One unique feature of the Zacuto Z-Crank is that it allows you to turn the follow focus wheel with a steering wheel spinning knob like on a car.  A whip can be used to pull focus if your focus puller wants to focus the camera without physically touching the camera.  This tool also prevents any camera operator body shaking or vibration from transferring to the camera.

Featured Filmmaker, Rui Vieira using the Zacuto Zwhip

The stationary white disk surrounding the wheel is used by the focus puller to mark his or her focal lengths and take care of the focus according to the marks he or she took during rehearsals. A focus puller often uses a measuring tape to correctly measure the distance from the lens to the subject, allowing for accurate marking of the disk.  If your subject moves closer to the lens or farther away from the lens, the focus puller will need to adjust the camera’s focus to keep the subject from becoming blurry (assuming your actors hit their marks).

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One Response to “Follow Focus Basics-Staying Focused”

  1. D Ben on August 26th, 2013 12:02 am

    8-25-2013: My Canon 16-35L 2.8 and 70-200 L 2.8 (Mark I & II) IS lenses work fine, as is, with my FF. No zipgear needed.

    Note: My thread/pitch interacting knob kept coming loose from the FF. Per a suggestion from Zacuto, I slightly squeezed the end of the rod, where the slot fits over the internal rod in the FF. No more problems. I used the pliers of my Leatherman, which has a curved gripping section. It had just enough play to sufficiently squeeze the slotted portion properly.

About the Author


Rachel has been with Zacuto since 2009. She began working in the sales department and moved to marketing in 2013. In her role as Digital Marketing Director she oversees the gear loan and review program, social media, blog content, zacuto.com, and works with the team on overall marketing strategy. Rachel has a BA in Theatre with a focus on Directing from Arizona State University. Those who have spoken with her on the phone know she occasionally reveals her homeland by slipping into a British accent. Rachel likes tear-jerker sports movies, reading cookbooks for pleasure, and crossword puzzles. Contact her at rachel@zacuto.com

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