Top-and-bottom or left-and-right split screen: which should you use?
Pick left-and-right when both halves are people facing each other or facing the camera — a conversation, a reaction, two performers side by side. Pick top-and-bottom when at least one half is something wide rather than a face — a workbench, a whiteboard, hands moving across a keyboard, a landscape shot. The two orientations are not interchangeable stylistic options; they crop the same camera footage in different directions, and that changes what survives.
DualCam offers both because a vertical canvas is not the shape a phone camera naturally produces, and there is no single crop direction that works for every subject. Knowing which direction each orientation cuts from lets you frame for the layout in advance, instead of finding out what got cut off after the take is already recorded.
Why the two orientations crop in different directions
DualCam’s canvas is 1080 pixels wide, either 1080×1920 for standard 9:16 or 1080×2340 to fill a modern iPhone screen — a tall rectangle either way. A single camera image, even once rotated for portrait shooting, is much closer to a landscape shape than the canvas is. Fitting that image into half the canvas is a crop, not a resize, and which edges get cut depends on which dimension that half of the canvas is short on.
Left-and-right split gives each camera the full height of the canvas but only half the width. Since the source image already has more width than a narrow half-canvas needs, DualCam crops in from the sides — in practice, close to a quarter of the frame disappears off each side. Top-and-bottom split does the opposite: each camera keeps the full width of the canvas, and the crop comes from the top and the bottom instead.
What that means for framing
Left-and-right: keep faces centred, expect the sides to go
Because the sides are what disappears, anything you want to keep near the edge of a left-right half — a second person stepping into frame, a sign on a wall, a hand reaching in from off to the side — is a gamble. Faces read fine in this layout as long as they stay near the centre of their half, which is exactly why it suits two people who would naturally sit across from each other in a conversation.
Top-and-bottom: keep the subject vertically centred, expect headroom and floor to go
A top-and-bottom half keeps the full width, so it is the better choice when the interesting part of the shot spreads out sideways — a workbench, a keyboard, a spread of ingredients, a wide gesture. What gets cropped here is vertical: too much headroom above a face, or a subject standing so their feet or the top of their head sit near the edge of the half, is what goes missing first.
You do not have to decide before you press record
Layout is one of the settings DualCam lets you change mid-recording, split orientation included, so a wrong guess early in a take is not a lost shot — switching to the other orientation partway through is a normal move, not a workaround. What is worth deciding in advance is not the layout itself but what each half of the frame is going to contain, because that is what determines which orientation crops the right things away.
The same reasoning applies to choosing between split screen and picture-in-picture in the first place: split works when both halves genuinely deserve equal space, and within split, the orientation follows from whether that space needs to be wide or tall.
Common follow-up questions
Does switching split orientation change the recorded resolution?
No. Resolution is one of the settings that locks the moment you start recording; layout, including which split orientation is active, is free to change throughout the take.
Is one orientation better for posting to short-video platforms?
Both fit inside the same 9:16 or full-screen canvas, so neither has an advantage there. The choice is about what survives the crop inside each half, not about the outer shape of the finished file.
Can you make one half bigger than the other in either orientation?
That is a separate setting from which orientation you pick — see the guide on making one side bigger in split screen for how the two combine.
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.