MOS

What this is about

Crews shoot MOS when sound would be useless or unnecessary — slow-motion inserts, drone shots, cutaways in loud environments, or shots that will only ever carry music. The slate is shown with fingers between the sticks or MOS written on it, so the editor never searches for audio that does not exist. The origin of the abbreviation is folklore with several competing stories; the practice itself is universal. Declaring MOS is a deliberate decision — dialogue accidentally shot MOS becomes an ADR bill.

A term only helps when everyone on set means the same thing by it — so what follows is how it is used, not a dictionary definition.

What runs differently here

In planning terms, that means:

• Slate MOS clearly — closed sticks or a hand between them
• Slow motion above sync frame rates is MOS by nature
• Never let a we-fix-it-later mood turn a dialogue setup into MOS

With TillyGen

Marking MOS setups in TillyGen's shot list tells both departments where sound can stand down and where it absolutely cannot.

Change one constraint and the consequences travel through the whole plan: affected shots are flagged, the call sheet is regenerated, and nobody keeps working from yesterday's version.