Slate
The identifying board held in front of the camera at the start of each take, recording scene, shot, and take information.
Slate
noun | Production
The board held in front of the camera at the beginning of each take, displaying identifying information about the shot being filmed: the production title, director, DP, camera roll number, scene number, shot designation, and take number. The slate is filmed for a few seconds before the action begins, creating a visual record that allows the editor and post-production team to identify and organise every piece of footage in the production. The term is used both as a noun (the object) and as a verb: "to slate a shot" means to film the identifying information at the start of a take.
Quick Reference
| Also Known As | Clapperboard, clapper, board, sticks |
| Domain | Production |
| Operated By | Clapper loader (2nd AC) or camera trainee |
| Contains | Production title, director, DP, camera, roll, scene, shot, take, date, day/night, int/ext |
| Related Terms | Clapperboard, Take, Coverage, Call Sheet, Principal Photography |
| See Also (Tools) | Shot List Generator |
| Difficulty | Foundational |
The Explanation: How & Why
A 20-day shoot on an independent feature generates 800 to 1,200 individual takes. Each one must be precisely identifiable in post-production, or the editor cannot locate specific takes, the sound editor cannot sync audio to picture, and the conform cannot match the correct digital file to the correct take in the edit. The slate solves this organisational problem by giving every take a unique, human-readable address: scene number, shot designation, and take number, filmed as a header before the action begins.
The slate's filmed information gives every take a unique identifier. The scene number tells the editor which part of the script the take covers. The shot designation (A, B, C...) identifies which specific camera setup within the scene. The take number identifies which attempt at that specific setup is being filmed. Together, scene + shot + take create a unique address for every piece of footage in the production.
The slate also serves an audio synchronisation function when used with a separate audio recorder. The clapperboard's hinged arm - the "clapper" - is snapped shut at the moment the slate is filmed, creating a sharp visual and audio event that can be matched in post-production to synchronise the separate picture and sound recordings. Modern digital production often uses timecode synchronisation instead, but the clap remains standard practice on most productions as a reliable backup sync point.
In digital production, the slate information is also entered into camera and sound metadata, but the filmed slate remains the most reliable and universally readable record - any editor, on any system, in any part of the world, can read a filmed slate regardless of what metadata system was used on the production.
Historical Context & Origin
The slate in its familiar clapperboard form developed in the late 1920s as synchronised sound production required a reliable method for matching separately recorded picture and sound. F. W. Thring, an Australian filmmaker, is credited with inventing the hinged clapper arm, with sound engineers Alan Mill and Harry Whiting responsible for the technical design. Leon M. Leon (1903-1998), a pioneer sound engineer, refined the combined slate-and-clapper assembly into the single unit used today. Before synchronised sound, slates were used purely for organisational identification - the earliest slates were literally made of slate stone, written on with chalk, hence the name. Digital slates with LED timecode displays were introduced in the 1980s but have not replaced the classic handwritten board on most productions. As NPR reported in 2014, even productions with full timecode sync still use the physical clap as a backup: "That's in case all this technology fails."
How It's Used in Practice
Scenario 1 - Slating a Take (2nd AC): Before each take, the 2nd AC holds the slate in front of the lens, reads aloud "Scene 14, Baker, Take 3" for the sound recordist, and snaps the clapper. The camera is recording; the sound is recording; the clap provides a synchronisation point. The 2nd AC steps out of frame; the 1st AD calls action. The take begins.
Scenario 2 - MOS Slate (2nd AC): A shot is being filmed without sound - a visual insert with no dialogue or sync sound required. The 2nd AC holds the slate as usual but does not snap the clapper, holding the arm closed with their hand between the boards to indicate no audio sync is needed. The notation "MOS" (Mit Out Sound - a production slang term of disputed origin) may be written on the slate.
Scenario 3 - Tail Slate (2nd AC): A documentary scene cannot be slated at the head because the action begins immediately and a slate would interrupt the moment. The 2nd AC films the slate at the end of the take instead, holding it upside down to signal to the editor that this is a tail slate rather than a head slate. The upside-down image is the convention identifying end-slating.
Usage Examples in Sentences
"Slate in - give me scene 22A, take 1."
"The editor cannot sync this take - the clap is off screen. Re-slate it."
"MOS - hold the sticks closed and note it on the slate."
"The tail slate is upside down. The editor knows it is an end-slate."
Common Confusions & Misuse
Slate vs. Clapperboard: These terms are often used interchangeably in professional practice. Technically, the "slate" is the board with the identifying information; the "clapperboard" is the complete assembly including the hinged arm. In everyday usage, "slate," "clapper," "clapperboard," and "board" all refer to the same object. "Sticks" is a common informal term.
Slate vs. Take: The slate identifies the take; it is not the take itself. The take is the complete recorded performance from action to cut. The slate is the identifying header filmed at the beginning (or end) of the take.
Key People & Films
F. W. Thring, head of Efftee Studios in Melbourne, is credited with the clapper arm's invention in the late 1920s, with his sound engineers Alan Mill and Harry Whiting responsible for the technical implementation. Leon M. Leon refined the combined slate-and-clapper into the universal design still used today. The 2014 NPR feature on slating, filmed on the set of Walk of Shame with 2nd AC Milan Janicin, documented how the smart slate's digital timecode chip interfaces with camera and sound recorder while the physical clap remains as a fail-safe. The clapperboard's cultural status as the universal symbol of filmmaking was cemented by decades of behind-the-scenes footage and films about filmmaking.
Equipment / Tools Reference
The Denecke TS-3 is a widely used smart slate with a built-in LED timecode display that jam-syncs from a master timecode generator. The Ambient ACN-2 ACL Ultra is another industry standard, featuring a high-contrast LED display and dual timecode inputs. Traditional wooden clapperboards from companies like Visual Departures remain standard on smaller productions. Sound Devices mixers including the 833 and Scorpio generate the master timecode that smart slates reference. ARRI and RED digital cameras accept timecode input directly via BNC connectors for automatic metadata sync.
Standards & Specifications
SMPTE 12M defines the timecode standard that smart slates display and that cameras and sound recorders use for electronic synchronisation. The standard was originally published as a single document and revised in 2008 into two parts: SMPTE 12M-1 and SMPTE 12M-2. ISO 9642:2020 defines time and control code for 24, 25, and 30fps motion-picture film systems, specifying digital code formats for timing, control, editing, and synchronisation. The SMPTE timecode system was developed by Leo O'Donnell at the National Film Board of Canada, using an 80-bit word derived from rocket telemetry. Frame rates of 30fps are standard for audio in NTSC regions; 25fps is standard in PAL regions per EBU recommendations.
Common Questions / FAQ
Q: Why do productions still use a physical clapperboard when digital cameras and sound recorders have timecode?
A: Timecode sync can fail - batteries die, cables disconnect, chips drift. The physical clap provides a visual and audio sync point that any editor can align manually, regardless of what metadata system the production used. It is a universal backup that requires no technology to read. Most productions use both: timecode for primary sync, the clap as insurance.
Q: What does MOS mean on a slate?
A: MOS indicates a shot is filmed without synchronous sound. The 2nd AC holds the clapper arm closed between the sticks to signal that no audio sync is needed. The term's origin is disputed - commonly attributed to a German-accented director saying "mit out sound," though this is likely apocryphal.
Q: What is a tail slate and why is it upside down?
A: A tail slate is filmed at the end of a take rather than the beginning, used when slating at the head would interrupt the action or destroy a spontaneous moment. The 2nd AC holds the slate upside down to signal to the editor that this is an end-slate, not a head slate.
Related Terms
- Clapperboard - The specific name for the hinged-arm slate used for audio synchronisation
- Take - The complete recorded unit that the slate identifies
- Coverage - The range of takes across different setups; the slate system organises all coverage
- Call Sheet - The daily document whose scene information is reproduced on the slate
- Principal Photography - The shoot during which all slating occurs
See Also / Tools
The Shot List Generator produces the scene and shot designations that are transferred to the slate for each setup, creating the organisational system that connects pre-production planning to post-production editing. For more on production workflow, see the blog post on scheduling and shot planning.
