Why do two people look different sizes in a split-screen interview video?
It is almost never the split itself. In DualCam, split screen — top and bottom, or left and right — always divides the canvas into two exactly equal halves; there is no adjustable divider that could quietly favour one side. What is actually different is what each half is filming through: the front camera on one side, a back-camera lens on the other, and those are two separate pieces of glass with two different fixed fields of view. Sit two people at the same distance from the phone and the two lenses still will not fill their half of the frame with the same amount of face, because they were never built to see the same amount of the world at a given distance.
This shows up most in a two-person interview specifically, because that is the setup where the phone genuinely stands between two people, one facing the front camera and one facing the back camera, per the guide on filming a two-person interview with one iPhone. A vlog or a reaction shot only ever asks one camera to hold a face at a time, so the mismatch has nothing to compare itself against.
Two lenses, not one crop
A face filling more of its half is a lens question, not a layout question. The front camera and each back-camera lens option are separate optics with a field of view fixed by the hardware, not by any setting in a dual-camera app. That property exists before DualCam draws a single pixel into the split-screen canvas — it is the same reason the front camera can look more zoomed in than the back camera even outside an interview, in any dual recording that puts both frames on screen at once.
Because it is a property of the two source images, no layout choice fixes it. Split screen and picture-in-picture both start from the same two mismatched frames; they just crop and place them differently.
Why the split-screen crop is not the cause
Split screen does trim both frames to fit — roughly a quarter off the top and bottom in a top-and-bottom split, or roughly a quarter off each side in a left-and-right split — but it does that evenly, to both halves, by the same fixed ratio every time. An even crop cannot be what makes one face read bigger than the other, because both faces lose the same proportion of their frame. The size difference you are looking at was already there in the two source images, before either one was cropped into its half.
It is worth ruling this out first, because it means reframing inside the crop will not solve it either. Centring a face better inside its half makes the composition tidier; it does not change how much of that half the face fills.
What actually narrows the gap
Break the symmetry in seating distance
The instinct in a two-person interview is to seat both people the same distance from the phone, since the setup already looks symmetrical with the phone standing between them. That is exactly what leaves the mismatch untouched. If one lens reads noticeably tighter than the other — commonly the front camera against the back camera’s default wide lens — let the person on that side sit a little further back, or bring the other person a step closer. You are not fighting the lens; you are giving each person a distance that happens to fill their half the same amount.
Pick a wider back lens before you record
On an iPhone with more than one back lens, switching from the wide lens to the ultra wide brings more of the scene into the same frame at the same distance, which is the real way to bring the two fields of view closer together. This has to be decided before you start recording — like resolution, the back lens is not on the list of things DualCam lets you change mid-take, so settle it during a quick test clip rather than mid-interview.
Leave pinch-to-zoom out of this fix
Zooming in on either preview crops and enlarges the image the lens already captured; it does not change what that lens sees. Using it to try to match two faces in size mostly costs you detail on whichever side you pinch, without touching the actual field-of-view gap that caused the mismatch.
Common follow-up questions
Can I just make one half of the split bigger to compensate?
No — split screen always divides the canvas into two exactly equal halves with no adjustable ratio. If you want one person to deliberately read larger than the other, that is what picture-in-picture is for, not an uneven split.
Which side usually needs to sit closer?
Whichever lens tends to read tighter for a given distance — often the front camera, next to the back camera’s default wide lens. Let that person move back slightly, or bring the other person forward, until the two faces read at a similar scale.
Does the same mismatch happen in picture-in-picture?
The underlying field-of-view difference is still there, because it belongs to the lenses, not the layout. It reads differently in picture-in-picture only because that layout already makes one camera dominant by design, so an uneven scale is less surprising there than it is in a split that is supposed to be even.
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