Does turning on Personal Hotspot stop a dual camera recording on iPhone?

Personal Hotspot never asks for the camera or the foreground

Personal Hotspot can be switched on from the toggle in Control Center or from Settings, and once it is on it runs as a background service: it watches for other devices to join and relays your cellular data to them over Wi-Fi, Bluetooth or a cable. None of that requires AVFoundation, the framework a camera app like DualCam uses to capture and record — Personal Hotspot has no reason to ask iOS for the camera, and iOS has no reason to give it up.

Turning it on from Control Center is the same overlay covered in the guide on whether opening Control Center stops a dual-camera recording: the panel is drawn above whatever app is running, not in place of it, so DualCam stays the frontmost app the entire time the panel is open. Flipping the Personal Hotspot switch inside that panel and swiping it away again never once takes DualCam out of the foreground.

Someone joining your hotspot happens on their screen, not yours

When another device connects to your Personal Hotspot, essentially everything about that handshake happens on the joining device — it is the one showing a Wi-Fi password prompt or an Instant Hotspot pairing screen, not yours. Your iPhone's side of the exchange is a background networking event: a device requests to join, gets authenticated, and starts using the connection. None of that opens an app, shows a full-screen prompt, or asks you to do anything on your phone.

That is why it does not matter how many devices join, or how long they stay connected, for a recording already in progress. A dual-camera session only cares about whether DualCam is still the frontmost app and whether the camera and microphone are still available to it — a fact about network clients joining and leaving has no bearing on either.

The connection indicator is drawn above the app, not into the frame

The small "Personal Hotspot" label or connection count that iOS shows near the top of the screen when a device is connected is system chrome, the same layer that draws the status bar, a notification banner, or the green dot that appears when a microphone is active. The guide on whether a notification shows up in a dual-camera recording covers the same mechanism in more depth: DualCam's recorded frame is built directly from the two camera images, composited on the GPU into a canvas 1080 pixels wide, and that pipeline never reads what iOS happens to be drawing on top of the app.

So the honest answer to "will my video show that a device just joined my hotspot" is no, for the same reason it does not show a text message arriving or the clock in the status bar changing. Whatever you see happen at the top of your own screen while you are filming is not a preview of what lands in the file.

The one way it can still end a take

There is exactly one path from Personal Hotspot to an ended recording, and it is not Personal Hotspot itself: if turning it on means picking up the phone and opening the Settings app — rather than pulling up Control Center — that is an ordinary app switch, the same one covered in the guide on whether switching apps stops a dual-camera recording. Settings becoming the frontmost app ends the take the instant it happens, and Personal Hotspot being the reason you opened Settings makes no difference to that rule.

The fix is simply which door you use. Control Center is an overlay and never touches the foreground; the Settings app is a real app and always does. If Personal Hotspot is already on before you start recording, none of this comes up at all — there is nothing left to toggle mid-take.

Setting it up so it never comes up mid-take

• Turn on Personal Hotspot before you start recording, if you already know someone will need it. That removes the only decision — Control Center or Settings — that could otherwise cost you a take.
• If it has to happen mid-recording, use Control Center, not Settings: swipe to open it, tap Personal Hotspot, swipe it away, and DualCam has stayed frontmost the entire time.
• Give the joining device your password ahead of time when you can. Fumbling to read it off your own locked screen mid-take is a more common way to accidentally open Settings than Personal Hotspot itself is.
• Remember that sharing a cellular connection is its own drain on the battery, on top of what two live camera feeds and a real-time composite already use — worth keeping in mind on a take you plan to let run for a while.