Does Continuity Camera stop you from recording dual camera video on iPhone?

One camera, one caller, regardless of which device is asking

iOS treats the iPhone's cameras as a resource one process can hold at a time. That rule is what makes a phone call or another app take the camera away from a recording on the same iPhone, and Continuity Camera does not get a special exception from it just because the thing asking is a different device. When your Mac is nearby, signed into the same Apple ID, and an app on it opens a camera picker, the iPhone can offer itself as that camera the same way a webcam plugged into the Mac would — and while it is doing that, its camera is the Mac's to use, not the iPhone's own apps'.

This is the same category of interruption as the ones a dual recording already has to survive — the phone getting a call, another app grabbing the camera, the system pulling it away under load — just arriving over a wireless connection to a second device instead of from something running on the iPhone itself.

Why the conflict mostly runs one way

Continuity Camera generally looks for an iPhone whose camera is free to hand over — sitting on a stand, screen dark or on its lock screen, not actively being used by something in the foreground. A dual recording in progress is the opposite of that: DualCam is the frontmost app, actively holding the camera open and writing frames to a file. In practice that is not the state a Mac reaches into and quietly repossesses. The realistic failure is the other order — the Mac already has the iPhone's camera when you go to open DualCam, and DualCam cannot get a session started because there is nothing free to start one with.

So the useful mental model is not "my Mac might cut off my recording." It is closer to "whoever asked first keeps it until they let go." If DualCam got there first and is already rolling, that possession is what the system is protecting, not what it is likely to give away.

What it looks like when this is the cause

A Mac using your iPhone as its camera puts a clear indicator on the iPhone's own screen for as long as that session runs — the phone tells you it is currently being used as a camera. If DualCam will not open its camera preview, or opens but shows nothing usable, that banner is the first thing worth checking before assuming anything is wrong with the phone or the app. It is not a DualCam error message, because DualCam never got far enough to raise one; the camera was never handed to it in the first place.

Freeing the camera before you record

• Look at the iPhone's own screen first — the indicator that it is serving as a camera for the Mac is the fastest way to confirm this is what is happening.
• End the session from either end: quit or leave the call on the Mac, or switch that app's camera source away from the iPhone, and the indicator on the phone clears on its own.
• You do not need to turn off Wi-Fi or Bluetooth to break the connection — that disconnects the specific camera session, not the whole feature, and turning radios off is a heavier step than the problem needs.
• If this keeps happening by accident on a Mac you use often near your iPhone, turning Continuity Camera off for that iPhone in the Mac's own system settings stops it from being offered as a camera option at all, rather than something you have to catch and stop each time.