MOS in Post Production


Posted June 5, 2023

M.O.S. It stands for “Mit Out Sound.”

Is that part of a James Cameron Terminator machine?

Or maybe some new AI I’m using to cut RECKONING instead of maintaining any creative involvement?

Virtual Crew, it’s neither. But I do like the Terminator option!

MOS means a take without sound — It happens all the time in movies.

(A “take” is the start and stop of camera recording when filming a scene)

So why MOS?

Maybe there’s no dialogue. Or the shot is too “wide” to get a mic in. Or the background ambience makes sound impossible. You know — traffic, frogs, screaming people.

MOS shots are identified in editorial when the 2nd AC holds the slate closed instead of “clapping” it — As my lovely wife demonstrates below.

So whaddaya do with MOS takes? This isn’t Charlie Chaplin!

“Foley sound.”

If you watch the credits of ANY Hollywood movie, you’ll notice foley artists mentioned.

They’re the blessed souls who recreate the sounds needed to match what the camera captured. And for a film like Pixar’s CARS, pretty much the entire film is foley.

When foley sounds are recorded, they’re delivered to the sound designers who meticulously place them.

You know…Foot steps. Coffee mug set down. Door knob turn. Face slap…

Oh wait, that was the Oscars.

I have an example of foley sound in RECKONING for you to check out below.

But first:

Imagine you’re the sound designer.

You watch Rose run up to a house and knock on the door — Just 9 seconds.

Upon observation you realize there is:

Running in the grass

Footsteps on stone steps

Footsteps on a wooden porch

Door knock

Background ambience

All of that for 9 seconds??? When’s lunch?

Watch it here

Yep, none of those sounds happened day of shooting.

All of them were recorded later (at different locations) and the ambience was pulled from a sound library.


A unique sound design item in addition to foley from last week:

Had to record ALL of Ghost’s lines.

Wait, what happened?

Wearing the mask during production meant there wasn’t a good way to get clean dialogue. So I had to take the mask out later and record all of his lines again.


Virtual Crew…That’s the latest.

Sound design isn’t glamorous. But it’s part of filmmaking.

And I love it!

Thanks for hanging with me.

Kyler Boudreau

P.S. Already have ideas for the next short film cooking. But even cooler? A feature film I want to shoot here in the mountains. As always, you’ll be the first to hear the details. Now I’ve gotta get back to work.

And don’t forget to send any aspiring filmmakers you meet to Write & Direct!