At the bottom of this post, a two-minute video explains it in an easy-to-follow way, with illustrations and side-by-side comparisons. Watch the video ▶
Inside this iPhone camera, six blades thinner than a human hair are moving.
This is the iPhone 18 Pro variable aperture, new this generation. But is it actually useful?
First, what is an aperture? It is the opening that controls how much light passes through the lens. Open it wide, and more light comes in. Naturally, that helps in the dark. A wide aperture is also what you need for a blurred background, also known as bokeh. Narrow it, and you get the opposite. The subject and the background come out evenly sharp.
Until now, this opening was fixed on the iPhone. Aperture size is written as a number.
The lower the number, the wider the opening, and the more light comes in. The iPhone 17 Pro had one setting, ƒ/1.78. The iPhone 18 Pro moves in four steps, from ƒ/1.48 to ƒ/4.0. At the widest setting, about 1.45 times more light comes in than before. Apple says low-light photos are about 50% better.
By default, the camera picks a step for the scene. You can also set the aperture value yourself.
So is it useful? We do not know yet. Early hands-on opinions were split. Tom’s Guide, a tech news site, reported a clearly different background blur. Engadget, another tech news site, found the difference hard to see. The demo was also indoors only. So low-light shooting, the main purpose of this feature, could not even be tested.
There is one more variable. The smaller the camera sensor, the less the aperture affects background blur. Smartphone camera sensors are generally small. And Apple did not disclose the sensor size this time.
There are limits too. It does not adjust in fine increments like a regular camera. It only moves between four fixed steps. Only the main camera has it. And the thin aperture blades and moving parts raise durability concerns.
The variable aperture is not a new idea. The Galaxy S9 and S10 had a two-step aperture. Samsung dropped it with the S20. It is a first for the iPhone, not a first for smartphones.
For all the features of the iPhone 18 Pro, and what changed from the previous generation, watch the full videos.
iPhone 18 Pro variable aperture Key numbers
- Aperture ƒ/1.48 to ƒ/4.0 in 4 steps (iPhone 17 Pro: fixed ƒ/1.78)
- About 1.45 times more light at the widest setting, low-light photos about 50% better (Apple’s claim, unverified)
- Main camera only, sensor size not disclosed
💡 FAQ
Q1. Does every iPhone 18 Pro camera get the variable aperture?
No. Only the main camera has it. The 13mm ultra-wide stays at ƒ/2.2 and the 100mm telephoto at ƒ/2.8, both fixed.
Q2. Can I set the aperture myself?
Yes. By default the camera picks a step for the scene, and you can also set it yourself. It does not adjust continuously, though: it only moves between four fixed steps, ƒ/1.48, ƒ/1.8, ƒ/2.8 and ƒ/4.0. The stock camera app also gained manual controls for shutter speed and white balance, plus a histogram.
Q3. Is a moving aperture a durability risk?
Blades thinner than a human hair and moving parts inside a phone raise durability concerns, and that criticism came up right after the launch. Apple says the blades use a material chosen with durability in mind, but as of this writing in October 2026 no endurance test results have been released.
Watch next
- 📝 Full specs and details 👉 iPhone 18 Pro Specs: What Do Variable Aperture and 2nm Change?
- Full video (12 min) 👉 iPhone 18 Pro 2nm Chip and Variable Aperture: What Actually Changes?
