Marked board held in front of camera at the top of each take, displaying scene, take, date, and camera settings so Cut and sound can sync in post.
Definition
The slate is a mechanical synchronization device consisting of a writable board (30×25 cm standard) with a hinged wooden bar that produces a distinct clap when closed. The device is used for precise audio-video synchronization in post-production by accurately marking the beginning of a take. The term derives from the characteristic clapping sound, with the English "clapperboard" coming from "clap".
Technical Details
Standard Slate: black board with white bars, writable with chalk or erasable markers. The upper bar measures 40×5 cm and is closed with a force of 15-20 Newtons. Digital Slates (Smart Slate) integrate LED displays with a timecode generator, precisely synchronized to 1/100th of a second. Color Slate for white balance combines gray, white, and black fields (18% gray according to Kodak standard). Night Slate uses a white board with black lettering for low-light situations.
History & Development
In 1929, American cinematographer Frank Thring introduced the first film slate at Warner Brothers. Originally a purely informational board, it was equipped with the hinged bar in 1931 for sound film synchronization. In 1980, Denecke Inc. developed the first timecode slate with a digital display. Modern Smart Slates, since 2010, wirelessly transmit metadata to cameras and sound devices, support GPS coordinates, and connect via Wi-Fi to the production database.
Practical Use in Film
On "Mad Max: Fury Road" (2015), the team used GPS-enabled Smart Slates for precise geolocation of the 480 camera setups in the desert. Christopher Nolan insists on analog wooden slates – even for "Interstellar," he eschewed digital alternatives. Multi-camera productions use master-slave systems: one main slate triggers up to 12 secondary camera slates synchronously via radio. Second unit shots require identical timecode settings to the main unit.
Comparison & Alternatives
Soft Clap replaces the wooden bar with foam pads for noise-sensitive recordings. Insert Slate marks subsequently inserted shots without a clapper sound. Digital workflows utilize Tentacle Sync devices, which automatically synchronize cameras and sound devices. VR productions use 360° slates without visible edges. For live streaming, the software-based Virtual Slate replaces physical slates with programmable overlays featuring automatic timecode matching.