iPhone 18 Pro aperture: how to change it and when to use each setting

Every earlier iPhone camera had a fixed aperture. The lens opened to one size, and the phone made up for the rest with software. The iPhone 18 Pro changes that. Its main camera can change the size of its opening, which changes how much light reaches the sensor and how much of the picture stays in focus. It is the biggest change to the camera hardware in years, and many people cannot find where to control it. This guide explains how the variable aperture works, shows where to change it in the Camera app, and says when each setting is worth using. We use Apple's own words from its launch page and its iPhone User Guide.

What does a variable aperture do?

The aperture is the opening that lets light into the lens. A lower f-number, such as f/1.48, means a wider opening. It lets in more light, which helps in dim places, and it gives a shallower depth of field, so the background looks softer. A higher number, such as f/4, means a narrower opening. It lets in less light but keeps more of the scene in focus, from near to far.

Apple says the iPhone 18 Pro uses six laser-cut blades controlled by a new rotor mechanism. The variable aperture is on the new 48MP Fusion Main camera, which Apple names as the one that has it. The other cameras are not described that way.

What are the iPhone 18 Pro aperture settings?

Does the iPhone choose the aperture for me?

Yes, by default. Apple says the Main camera adjusts the aperture on its own by automatically adjusting for depth of field and lighting. Most photos need no action from you. You only need the manual control when you want a particular look, such as a very soft background or sharp focus across a group.

How to change the aperture on iPhone 18 Pro

Apple's launch page says you can manually adjust any of the four aperture settings in the Camera app, and that Pro controls let you adjust lens aperture, shutter speed and white balance, or use a histogram to check exposure. The steps below follow Apple's iPhone User Guide for iOS 27, as summarized for us, because the guide page itself would not load in full. Menu names can differ a little on your phone.

How to keep your aperture setting

The camera normally resets your choices when you close the app. Apple's guide says to turn on Lens Aperture in Settings, Camera, Preserve Settings if you want the camera to remember it. We cover Preserve Settings in our guide on camera settings that keep resetting, including the other switches and how to test them.

When should you use each setting?

• Dim restaurant or evening scenes: try f/1.48, which Apple says is for low light. The photo will be brighter, and the background will blur more.
• Portraits of one person: f/1.8 is Apple's pick, a balance of light and depth of field.
• Groups, landscapes and buildings: use f/4, which keeps more of the scene sharp.
• Moving subjects or video: leave the camera on automatic unless you have a reason, because a wide opening in a bright place can overexpose a scene.

These are starting points. Take two or three shots at different settings and look at them. Our guides on the shutter speed and on the aspect ratio cover the other controls you may use with aperture.

What does aperture not fix?

A wider aperture does not fix a shaky hand, a dirty lens or a moving subject. If your photos look blurry, clean the lens with a soft cloth and read our guide on blurry iPhone photos. Aperture also does not change the zoom or the field of view. It only changes light and depth of field.

How aperture works with shutter speed and brightness

Aperture is one of three things that decide how bright a photo is. The second is shutter speed, which is how long the sensor collects light. The third is how sensitive the sensor is, which a phone chooses on its own. If you open the aperture wider, the phone can use a faster shutter speed for the same brightness, and a faster shutter helps freeze motion. If you narrow it to f/4, the phone needs more light or a slower shutter, so it may blur moving subjects in dim places. That is why f/4 suits bright, still scenes, and why the automatic mode picks a wide opening when it gets dark.

What else do Pro controls let you adjust?

Apple's launch page says Pro controls are a customizable Camera app experience on the iPhone 18 Pro and Pro Max. You can adjust settings such as lens aperture, shutter speed and white balance, and you can use a histogram to check exposure. A histogram is a small graph of how light and dark your picture is. If the graph is bunched against the left side, the photo is too dark. If it is bunched against the right, it is too bright. It is a handy check when a bright screen makes the preview hard to judge.

Tips for better photos with a wide aperture

• Tap the subject to set focus before you shoot, because a wide aperture gives you less room for focus errors.
• Move closer to the subject if you want a stronger blur in the background.
• In dim light, hold the phone steady with both hands or rest it on something, since a wider opening still needs a steady hand.
• Check the result by zooming in on the photo, not only on the preview.
• Switch back to automatic when you are in a hurry, because it works well most of the time.

Do other iPhones have a variable aperture?

Apple's launch page describes it on the iPhone 18 Pro and iPhone 18 Pro Max. Its page on the iPhone Duo does not say whether the Duo has it. Earlier iPhones have a fixed aperture. If you buy a model, check Apple's current specifications for your exact phone.

Can apps use the variable aperture?

Apple says developers get an API for even more control across the aperture range in their apps. That means a third-party camera app may offer the same control. You do not need to do anything in the Camera app for that. Check each app's settings.

What do Apple's pages not say about the aperture?

• Which f-number is the fourth setting. Apple names three on its launch page, and news sites report f/2.8.
• Whether you can change the aperture after you take a photo. The pages we read do not say.
• Whether the Ultra Wide or the Telephoto camera has a variable aperture. Apple describes it on the Main camera only.
• Whether the iPhone Duo has the same control. Apple's Duo page does not say.

Still cannot find Lens Aperture?

Make sure you have an iPhone 18 Pro or Pro Max, that iOS 27 is installed and that you are using the Main camera in a supported mode. Update the software in Settings, General, Software Update. If the control is still missing, restart the iPhone, and check Apple's iPhone User Guide for your exact version, since menu names can change.