Guide to Using a Clapperboard: How to Mark a Film Slate

A film slate is a filmmaking tool used during film production to help synchronize the audio and video in post-production. A film slate is made of two components: hinged clapper sticks and a board. Before a director calls "Action!" the second assistant camera (also called the second AC or clapper loader) claps the ticks together to make a loud, distinct "clap" noise. In post, the film's editor ensures that the audio is synced by finding the "clap" in the audio track and matching it to the moment in the video when the clapper sticks close. The board on a film slate displays important information, like the scene number and take number, that is useful for organizing footage.

Film slates go by several alternative names such as “clapperboards,” “clapboards,” “markers,” “slate boards,” and “sync slates,” but they’re always just called “slates” on set.

In the golden age of Hollywood, film slates were made of wooden chalkboards, but today you'll find two main types of slates:

• Standard film slates: These typically consist of wooden clap sticks on top of an acrylic dry-erase whiteboard.
• Time code slates: Also called "smart slates" or "clock slates," time code slates are equipped with a digital clock. This clock displays a time code that is synchronized with the camera and audio recorder. This allows an editor to sync up the audio and video without needing to listen for the clap.

The clapper sticks for both slate types feature alternating black and white diagonal stripes that are designed to be visible in front of any background. Some slates have colored stripes that are useful for color calibration in post.

The film slate contains both general information about the production and information specific to each individual shot:

1. 1. Production title: Write the name of the production.
2. 2. Director: Write the name of the director.
3. 3. DP: Write the name of the director of photography (also called the cinematographer).
4. 4. Camera: Write the name of the camera operator or the letter associated with the camera (different cameras are referred to as A-cam, B-cam, C-cam, etc).
5. 5. Date: Write the date the footage is shot.
6. 6. Roll: This number identifies the film roll or digital media card onto which the shot is recorded.
7. 7. Scene: This number identifies which scene is being filmed. A scene generally includes multiple shots, which are indicated by adding letters to the scene number. For example, the first shot of scene number three is labeled "3," the second shot is labeled "3A," the third shot is labeled "3B," and so on. Always skip letters "I' and "O" when labeling shots because they look too similar to the numbers one and zero.
8. 8. Take: This number identifies the current take. A take is an individual version of a specific shot. For example, when a director films the same shot a second time, it’s called "take two."

Some slates have additional sections that allow you to indicate the camera frame rate (fps), whether the shot is day or night, and whether the shot is interior or exterior. It's the script supervisor's job to determine the proper scene and take numbers, so if you're ever unsure how to label either of these items, check with the script supervisor.

Slating is a relatively simple task, but it requires patience and attention to detail.

• Mark the film slate. Fill in every box on the slate with the appropriate information, adjusting the scene and take numbers each time they change.
• Wait until the camera is rolling. Get into slating position after the first assistant director (also called the first AD) calls out that it's time to roll on the take. Once the camera operator and production sound mixer shout out that camera and sound are speeding, begin slating.
• Hold the slate in frame. The camera operator will instruct you where to stand and hold the slate so that it's clearly visible in the frame and in focus. Hold the film slate with the hinge facing you, so that you can open and close the clapper sticks with one hand. Once you're in position, open the sticks and tilt the slate forward slightly to avoid reflecting light into the camera lens.
• Say the scene and take numbers aloud. Call out the scene number, take number, and then yell "Mark!" When there's a letter in the scene number, say a full word that begins with that letter for clarity. For example, if your film slate reads "scene 5A, take 2" then a proper call out would be: "Scene five apple, take two. Mark!"
• Clap the sticks. After you verbally call out the slate, clap the sticks together. Close the clapper sticks using a moderate amount of force; the sticks don't need to be slammed together to create enough sound. Immediately after clapping the sticks, lower the film slate, and walk out of frame.
• Use second sticks if you make a mistake. In the event you don’t slate correctly the first time—maybe you held the slate out of frame, didn’t clap the sticks loudly enough, or the sound wasn’t recording yet—call out "second sticks" before slating again. This alerts the editor that the first slate was false.
• Use a tail slate when necessary. Sometimes you can't slate before a take because of the required lens focus or framing of the shot, so a tail slate is necessary at the end of the take. To perform a tail slate, hold the slate upside down, clap the sticks, flip the slate right-side-up so it's readable, and then call out the information on the slate's board.
• Use soft sticks for closeup shots. When filming a closeup, you may need to hold the film slate directly in front of an actor's face. To avoid disturbing the actor, call out "soft sticks" and clap the sticks softer than usual. This signals to the editor to listen extra closely for the clap sound.
• Indicate M.O.S. for takes without sound. This acronym stands for "motor only sync" or "motor only shot," and it means the take is being filmed without sound. To indicate a M.O.S. take, hold the slate with your hand between the two clapper sticks and refrain from clapping them.

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