Audio and camera record separately with timecode sync — industry standard during production. Sound mixer controls quality, not camera operator.
On set, we deliberately separate sound and image — this is the reality of professional production. The camera records video, the sound engineer operates a separate audio device (usually a Zoom F8n, Sound Devices MixPre, or similar), and both synchronize via timecode. This sounds technical, but it's a liberating way of working: the sound engineer has full control over microphone placement, gain structure, and monitoring — independent of what the camera is doing. The camera doesn't have to worry about quality, only about the timecode trigger.
In practice, it works like this: we set up a timecode source on location — usually a wireless sync between camera and recorder — and start both synchronized to the slate. The sound engineer constantly monitors via headphones, adjusts levels according to the scenario (outdoor shoots require different levels than enclosed spaces), and notes problems: wind noise on take 3, airplane noise on take 5. While the camera saves in uncompressed format or codec XYZ, the recorder can work at a higher resolution (24-bit, 48 kHz) — that's the advantage. In the edit, the editor later synchronizes both files via the common timecode, often even automatically via a plugin.
The alternative — sound directly in the camera — leads to compromises: the cinematographer is afraid of clipping, the sound engineer is too far away, and inquiries about levels take minutes. With double-system, these conflicts don't arise. The sound engineer is master of their medium, just as the gaffer is master of light. This is also the psychological point: sound isn't bonus material that runs alongside. Sound is the main course.
There are still drawbacks — especially with gimbal or Steadicam shots, where the sound engineer has to follow the lens without entering the frame. Wireless systems can have dropouts in urban environments. And in the edit, synchronization costs time (if timecode lock fails, manual correction is necessary). For long-form content, series, cinema: indispensable. For fast documentaries or run-and-gun, it is sometimes neglected — unjustly.