The iPhone 18 Pro and iPhone 18 Pro Max both use a 48MP Fusion main camera with a variable aperture that moves between f/1.48 and f/4, built from six laser-cut blades. It is the first iPhone main camera that can physically change the size of its lens opening.
Every earlier iPhone shipped with a fixed aperture, so the camera could only control exposure with shutter speed, sensor sensitivity and software. The new lens adds the third control that dedicated cameras have always had, and according to Apple’s announcement it is on both Pro sizes rather than reserved for the Pro Max.
What the f-number tells you
The f-number is the ratio of the lens focal length to the diameter of the opening, so a smaller number means a bigger hole. At f/1.48 the blades are almost fully open, and at f/4 they close down to a much smaller circle.
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The gap between the two ends is a little under three stops. In practical terms the f/1.48 setting lets in roughly seven times as much light as f/4, which is a wide range for a lens this small.
What each end of the range does to a photo
| Setting | Light gathered | Depth of field | Typical use |
|---|---|---|---|
| f/1.48 | Most | Shallow, background softens | Portraits, dim rooms, night scenes |
| In between | Moderate | Moderate | Everyday shots where the phone balances both |
| f/4 | Least | Deep, more of the scene sharp | Landscapes, group photos, bright sunlight |
Depth of field is the slice of the scene that looks sharp. Opening the aperture narrows that slice, which is how a camera separates a face from a busy background without leaning on software blur.
Closing the aperture to f/4 does the opposite. A group of people standing at different distances, or a skyline with foreground detail, will hold focus from front to back more easily.
In bright sun a narrow aperture also gives the camera room to use a slower shutter without overexposing, which tends to matter more for video than for stills.
How much of this you actually have to manage
Apple’s announcement says the Camera app now includes manual aperture and shutter speed controls, so you can pick a setting yourself. Apple has not described how the automatic mode decides which aperture to use when you leave it alone.
For most people the sensible approach is to leave the camera on automatic and treat the manual option as something to try for portraits and night scenes. Apple also says Night mode is faster on the new models, though it has not spelled out how much of that comes from the wider aperture.
Pre-orders open Saturday, September 12 at 5 a.m. PT, with the phones arriving Friday, September 18. Pricing starts at $1,199 for the iPhone 18 Pro and $1,299 for the Pro Max, and the aperture range is identical on both.
