Can you change which camera is the main view while recording?
Yes, in a picture-in-picture layout. The camera filling the whole frame and the camera floating in the small window are not fixed roles — you can swap them, and in DualCam that swap works while you are still recording, the same as moving the inset to a different corner or changing its size.
The swap looks simple on screen, but it is worth understanding what it actually does before you rely on it, because the two positions in a picture-in-picture layout are not equivalent. One of them keeps the full image; the other gives some of it up.
The two roles are not the same shot
A picture-in-picture layout has one camera filling the whole canvas and one camera cropped down into a small window. The full-frame camera gets the whole picture — a phone camera produces a 16:9 image, and a 9:16 vertical canvas is that same shape rotated, so the source fits with nothing thrown away. The inset does not get that deal: it is a smaller window carved out of the frame, and depending on its shape it can lose a meaningful part of the image to get there.
So swapping which camera is main is not a cosmetic flip. It decides which feed keeps its full detail and which one gives some of it up to fit a corner of the screen.
What is free to change mid-take, and what is not
DualCam locks resolution, the mute switch and the countdown timer the instant you press record, because each of those changes how the output file itself is built. Everything about layout sits on the other side of that line: which layout you are using, the inset’s corner, its size, its shape, the colour filter, and which camera is currently the main one can all be changed while the camera is rolling.
That is why the swap is worth treating as a real creative tool rather than a setting you get right once and leave alone. It costs nothing to change your mind mid-recording, the way it would cost something to change resolution mid-recording.
When the swap is actually worth doing
The common pattern is a shot that starts with one camera doing the work and ends with the other one taking over. A walk where you are narrating what the back camera sees, then stop and turn to speak straight to the lens. A tutorial where your hands lead through most of the video, but the opening line and the closing thought read better with your face filling the frame. A demonstration that spends most of its time on what is being shown, with a taste, a reveal or a result that calls for a close look at your own reaction.
In all of these, the swap follows a change in what the video is actually about at that moment, not a random cut. Do it at a natural pivot — a pause, a change of subject, a look toward the lens — and it reads as an intentional edit rather than the app doing something to the shot.
What the swap does not touch
Audio is unaffected either way. A dual recording writes one audio track for the whole file, not one per camera, so there is nothing about the sound that changes when the visual roles swap.
The swap is also independent of the inset’s corner, size and shape — those are separate controls, and you can combine a swap with, say, moving the small window to the opposite corner for a bigger visual change in one motion.
It becomes part of the file the moment you do it
Whatever the arrangement is at the instant a frame is drawn, that is what gets written to disk — the preview and the recording are the same rendered image. Once you have swapped and kept recording for a few seconds, that composition is baked into those frames the same way a colour filter or a layout choice is, and there is no pulling the two camera feeds back apart afterwards to redo it in an editor.
If you are not sure a swap will read well, the cheap fix is not fixing it in post. It is doing a second take without the swap, or with it at a different moment, since starting over costs a few seconds and re-splitting a finished file does not really work.
Common follow-up questions
Does swapping the main camera affect the audio?
No. There is one audio track for the whole recording, shared by both cameras, so nothing about the sound changes when you swap which one fills the frame.
Does the video quality change when I swap?
The overall file resolution stays the same, but which feed is sharp can shift. The full-frame camera keeps its whole image; the inset is a smaller window that can crop into the source depending on its shape, so swapping changes which camera is giving up detail to fit that window.
Can I do the same swap in split screen?
Split screen already gives both cameras equal space, so there is no big-camera, small-camera role to swap in the first place. The equivalent decision in a split layout is switching to picture-in-picture if you want one camera to lead.
Want to just do this?
DualCam records the iPhone front and back cameras at the same time and writes one finished MP4 while you shoot. Free, no account, no ads, nothing leaves the phone.