The iPhone 18 Pro is the first iPhone with an aperture that moves, and the four stops Apple lists, f/1.48, f/1.8, f/2.8 and f/4.0, are a genuine first. What they are not is a change to the whole camera system: the mechanism sits on one lens of four, and a good deal of the phone works exactly as it did before.
Six laser-cut blades open and close behind the 48MP Fusion main camera at 24 mm. Everything below is what that does not touch, drawn from Apple’s tech specs rather than from anyone’s experience, because no reviewer has shot with this camera yet. For what the stops are for, see our guide to the variable aperture system.
| Key facts | What Apple publishes |
|---|---|
| Lenses with a moving aperture | One of four |
| Stops | f/1.48, f/1.8, f/2.8, f/4.0 |
| Widest setting vs iPhone 17 Pro | f/1.48 against a fixed f/1.78, about half a stop |
| Focal length | 24 mm, unchanged from iPhone 17 Pro |
| Optical zoom steps | 0.5x, 1x, 2x, 4x, 8x, unchanged by aperture |
| Body depth | 8.75 mm on both models, the same as iPhone 17 Pro |
1. The other three cameras stay where they are
| Camera | Focal length | Aperture | Variable |
|---|---|---|---|
| 48MP Fusion Main | 24 mm | f/1.48 to f/4.0, four stops | Yes |
| 48MP Fusion Ultra Wide | 13 mm | f/2.2 | No |
| 48MP Fusion Telephoto | 100 mm | f/2.8 | No |
| 18MP Center Stage front | Not published | f/1.9 | No |
Three of the four cameras have a single fixed opening, exactly as they did on the previous generation. A group shot framed on the Ultra Wide, or a portrait at 100 mm on the tetraprism telephoto, gets no aperture choice at all.
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2. It changes nothing about reach or framing
The main camera is still a 24 mm equivalent at every stop, and the optical steps Apple lists remain 0.5x, 1x, 2x, 4x and 8x. Aperture controls how much light arrives and how deep the zone of sharp focus runs. It does not move you closer to anything.
The same is true of resolution. The 12MP 2x crop at 48 mm still comes off the same 48MP sensor, and Apple’s photo options are unchanged at 24MP and 48MP.
3. There is no more light above f/1.48
f/1.48 is the ceiling, and measured against last year’s fixed f/1.78 it is worth about half a stop. Apple’s separate claim of around 50 percent better low-light performance for the camera comes with no published test conditions, so it is not a figure to convert into stops.
Every other stop subtracts. Closing to f/4.0 removes a little under three stops of light compared with f/1.48, which is why the interesting half of this feature is the narrow end, not the wide one. Comparisons with the iPhone 17 Pro camera that lead on low light are describing the smaller of the two changes.
4. It did not cost the phone any thickness
Both models measure 8.75 mm deep, the same figure Apple published for the iPhone 17 Pro generation, and the 6.3-inch model keeps the 150.0 by 71.9 mm footprint. Weight went from 206 g to 211 g on the smaller Pro, with the Pro Max at 249 g.
A moving iris sharing a stack with optical image stabilization is a real piece of engineering, and it arrived without a thicker body. Both sizes get it, so the choice between iPhone 18 Pro and Pro Max is not a camera decision on this point.
5. Portrait mode has not been replaced
Apple still lists next-generation portraits with Focus and Depth Control, plus Portrait Lighting with six effects. Those are computational tools, and they remain in the app alongside the mechanical one.
The difference is where the effect happens. A physical aperture changes the light before it reaches the sensor. Depth Control changes the picture afterwards. Apple has not published anything about how the two interact, or whether choosing a stop manually limits what Portrait mode can do with the result. On the foldable, iPhone Duo relies entirely on the computational route with a fixed f/1.6 main camera.
What Apple has not said
- Whether positions between the four listed stops are available.
- Any depth-of-field figure at any stop, in feet, meters or anything else.
- The true focal length and sensor size, which would be needed to work out the physical opening.
- How the aperture interacts with close-focus shooting, which Apple has not described for this camera.
- Whether the narrow stops are usable handheld in anything other than bright light.
Pre-orders open at 5 a.m. PT on Saturday, September 12, and the phones reach stores on Friday, September 18, which is the first date anyone outside Apple can test a claim on this list.
