Set up a fair camera test

Apple says the iPhone 18 Pro and Pro Max use a variable aperture on the 48MP Fusion Main camera. The Camera app can adjust it automatically or let you choose from four manual settings. Apple illustrates a wide ƒ/1.48 opening for low light and a narrow ƒ/4 opening for more depth in a group photo. These details come from Apple's camera announcement.

To learn what changes, keep the phone in the same place, photograph the same scene within seconds, and compare the images at full size. This is a test plan, not a claim that we have independently measured camera performance. Our aperture explainer covers the basics first.

1. A group at different distances

Ask two people to stand at different distances from the camera in good light. Take one photo on automatic, then one with a narrower aperture. Compare the eyes of the nearer and farther person. Apple specifically points to improved detail toward the back of group photos when the aperture narrows.

If both photos look equally sharp, keep the automatic setting for similar situations. Distance, focus, and available light still matter.

2. One person against a busy background

Place a subject a few steps in front of a busy background. Compare the automatic setting with a wider manual opening. Look at the subject's face and the background detail. A wider opening can make the background look softer, but the result also depends on how far the subject is from the background.

Keep Portrait mode as a separate comparison. Its software depth effect is not the same thing as the lens's physical aperture.

3. A still subject in low light

Choose a scene that will not move, such as a lamp beside a book. Compare automatic with a wider aperture. Check whether letters and edges stay clear and whether bright areas retain detail. Apple says the camera can widen to ƒ/1.48 in low light, but image processing and exposure decisions also affect the result.

Repeat once with a person who moves slightly. If a narrow aperture forces a longer exposure, movement may matter more than extra depth of field.

4. Motion with Pro controls

Photograph a moving subject in daylight. Apple says Pro controls can adjust shutter speed as well as aperture. Change one setting at a time: first hold shutter speed steady while comparing apertures, then test shutter speed separately. Otherwise it is hard to know which control caused a difference.

Look for blur in the moving subject and detail in the background. Do not treat a single result as a verdict on the camera; repeat the shot to account for timing.

5. A short video clip

Film the same simple scene twice, with a person moving in front of a background. Compare the focus and the look of the scene as light changes. Apple's free Final Cut Camera update also supports variable aperture controls on iPhone 18 Pro, including aperture priority and shutter priority for creators; see Apple's update notes.

Keep the clips only if they teach you something. If repeated tests fill your library, use our 20-minute photo cleanup checklist to pick the best frames and remove accidental takes.