Lux Optics' Halide Mark III camera app now supports the variable aperture on the iPhone 18 Pro's main camera, and it goes further than any rival: where Apple's native iOS camera app restricts aperture adjustment to four presets, Halide lets photographers exercise more granular control over the setting than any other third-party app currently offers.

The update, released for iPhone and iPad, lands roughly alongside the iPhone 18 Pro Max itself, whose main camera hardware introduced the variable aperture that all of these software features depend on. Halide is not the first alternative camera app to embrace the new capability. Blackmagic Camera and Moment Pro Camera II both added variable-aperture support earlier, expanding the available range from Apple's four presets to ten presets in 1/3-stop increments — a step structure familiar to anyone who has used a conventional digital camera.

Halide Mark III pushes past that. The app, which Lux Optics positions as an "anti-algorithm" camera tool — meaning it favors photographer control over computational processing — now allows more finite aperture adjustment than either Apple's own app or the Blackmagic and Moment alternatives. For a hardware feature that Apple itself exposes only through a narrow set of presets, the software gap is notable: the most flexible control over a flagship sensor's optics comes not from the device maker but from a small independent developer.

The update also adds two new photography "looks" to the app, extending Halide's existing set of processing styles.

The competitive picture here is straightforward. The iPhone 18 Pro's variable aperture is the key optical change on the new flagship's main camera, and control over it is the dividing line between camera apps. Apple's native app treats aperture as a coarse, preset-driven setting. Blackmagic and Moment matched the 1/3-stop granularity that dedicated cameras have used for decades. Halide has now staked out the top position on that axis, which matters to the enthusiast photographers who make up the paying audience for these apps.

Halide Mark III is available on the App Store. With Apple's own app still capped at four presets, and rivals at ten, the aperture-control race among third-party developers is likely to tighten as more apps race to support the iPhone 18 Pro's hardware — and as Lux Optics defends the fine-grained control that currently distinguishes its update.