One of the questionable limitations of the iPhone 18 Pro's new main camera with a variable aperture is that you're limited to just four settings in the native iOS' camera app in manual mode: f/1.48, f/1.8, f/2.8, and f/4. Those same limitations are also in place when the app is adjusting the iris itself in Auto aperture mode, but it turns out that's not a strict limitation of the iPhone's camera hardware. Apple's SDK allows third-party camera apps to implement more granular control of the aperture.
BlackMagic Design's well-featured and still completely free BlackMagic Camera app for iOS was one of the first third-party options to introduce …