Final Cut Camera can now set the iPhone 18 Pro aperture, and Apple lists four stops rather than a rangeFinal Cut Camera can now set the iPhone 18 Pro aperture, and Apple lists four stops rather than a range

Apple released version 2.4 of Final Cut Camera on 29 September, adding control of the iPhone 18 Pro variable aperture to its professional filming app for iPhone.

Apple describes it as a free update. Alongside the aperture control, version 2.4 adds aperture priority and shutter priority modes to the existing manual controls, professional video scopes including an RGB parade and a histogram, clean SDI output through an HDMI-to-SDI converter, and a genlock offset for synchronising with other cameras. MacRumors reports a redesigned interface giving quicker access to shutter angle, ISO and white balance, customisable overlays with false colour and clipping indicators, focus peaking with an adjustable sensitivity, a tally light showing recording status, and a two-finger tap that clears the viewfinder. Apple also says Cinematic mode effects can now be applied to ordinary video, including footage shot in ProRes and Apple Log, with the focus point and depth of field adjustable afterwards on the timeline in Final Cut Pro.

How many apertures are there actually?

Four. Apple's own specifications page for the iPhone 18 Pro lists the 48MP Fusion Main camera at 24 mm with variable aperture, and names the values: f/1.48, f/1.8, f/2.8 and f/4.0. The same specification is given for the iPhone 18 Pro Max. MacRumors reported on 9 September that the mechanism uses six laser-cut blades moving between four settings, which matches.

This is worth stating plainly because the reporting is loose about it. 9to5Mac described the capability as a range from f/1.48 to f/4, which reads as a continuous sweep. Apple's specifications page lists four discrete values and no intermediate ones, and where a secondary source and Apple's own spec sheet disagree on a number, we follow Apple. Apple's Newsroom announcement of the update, for its part, gives no f-stop values at all.

Can other camera apps set the aperture?

The reporting says yes and nobody has named the mechanism. MacRumors wrote on 9 September that variable aperture is exposed to developers through a new API giving third-party apps access to the same settings, but named neither the API nor the framework. Apple's Newsroom post announcing Final Cut Camera 2.4 does not mention developer access at all, and carries no API reference, no framework name and no documentation link. A thread on Apple's own developer forums asks whether iOS 27 provides a way to set the aperture and whether it would be limited to the discrete settings or accept a continuous value, in the way focus does. It has no answer on it.

So the honest position is that a developer-facing control is reported to exist and is not documented anywhere we can point a reader at. We are not going to name an API that no source names.

Our take

Strip away the feature list and this is Apple shipping a hardware capability in its own app first, which is the pattern rather than the exception, and the pattern is not the complaint. The complaint is the documentation gap underneath it. A camera feature announced in September with a shipping first-party implementation at the end of the same month, and no named API three weeks after the phone went on sale, leaves every other camera app on the store in the position of knowing a capability exists and not knowing how to reach it.

The four-stops-not-a-range detail is the one APPDOOK would put in front of anyone building a camera interface this quarter, because it is the difference between two entirely different controls. A continuous range wants a slider or a dial, and it invites you to animate between values. Four fixed stops want a segmented picker, because a slider that snaps to four positions is a control lying about its own resolution, and users read that as a bug in your app rather than a property of the lens. Anyone who read the range framing and started sketching a dial has built the wrong thing, and it is a cheap mistake to avoid and an expensive one to discover in review.

Two things the sources genuinely do not say, and both are load bearing. Nothing states whether the aperture can be changed mid-recording or only set before a take, which matters enormously, because a mechanical iris moving during a shot is either a creative tool or a ruined clip depending on how fast and how quietly it travels. And nothing states what happens to the other two cameras when the main one stops down, or whether the system will override a chosen aperture in low light the way it overrides other manual settings. Apple's specification page is a list of values, not a description of behaviour.

The wider point is about what a variable aperture is for on a phone. Every other lens Apple ships is fixed, and computational photography spent a decade making a fixed aperture not matter by simulating depth of field in software. Putting a real iris back in is Apple conceding that the simulation has a ceiling, and the Cinematic mode change in this same release says the same thing from the other direction: you can now apply the synthetic version to ordinary footage and adjust it afterwards. Apple is shipping both the optical answer and the computational one in the same update, and it has not said which it expects people to reach for.