iPhone 18 Pro camera review: What ƒ/4 changes

The iPhone 18 Pro’s variable aperture changes depth of field and can turn bright points into starbursts, but ƒ/4 is not an automatic landscape upgrade. In one ƒ/4 landscape example, photographer Alex Armitage reported greater depth of field, but said the image blended two iPhone frames to recover highlights; he also noted some diffraction-related loss of sharpness (Armitage’s review).

What variable aperture changes

Apple gives the iPhone 18 Pro’s 48MP Fusion Main camera four aperture settings: ƒ/1.48, ƒ/1.8, ƒ/2.8, and ƒ/4.0. Aperture is the opening that controls how much light reaches the sensor; depth of field is the range of a scene that appears sharp from front to back. A lower f-number means a wider opening. Apple describes ƒ/1.48 as useful for low light and ƒ/4.0 for greater depth of field and starbursts from bright lights. Its camera specifications list these settings for the main camera, not the other rear modules.

That means the aperture choice is part of composing with the main camera. The Ultra Wide and Telephoto have fixed apertures, so they don’t offer the same adjustment. NeoTeo previously covered the feature in its earlier iPhone 18 Pro camera coverage.

In a Photolari review published October 13, 2026, the publication described a visible but subtle depth-of-field change between wider and narrower settings. It found little practical difference between ƒ/1.48 and ƒ/1.8, and said automatic mode often selected ƒ/1.8 in the lighting conditions it tried. That makes the widest setting less of a guaranteed visual switch than the four-number range might suggest.

At ƒ/4, bright points can take on star-shaped rays. Apple describes that effect, and India Today Tech reported seeing it around festive lights in photographs taken at ƒ/4 in a report published October 13, 2026. A Reddit user discussing the iPhone 18 Pro Max also said star-shaped highlights appeared in their photos at settings narrower than ƒ/1.48 and found them unwelcome for manual shooting; other commenters described the effect as a creative look. The reactions show why starbursts can be a compositional choice for one shot and an annoyance in another.

What ƒ/4 can cost in a landscape

A smaller aperture can keep more of a scene in focus, but that alone doesn’t guarantee a better landscape image. In his reported ƒ/4 example, Armitage said he combined two iPhone frames to restore highlights and observed some diffraction-related sharpness loss. Diffraction is a light effect that can soften fine detail; his result captures a trade-off in that particular scene, not a universal outcome for every ƒ/4 shot.

What the Camera app lets you control

Apple lists aperture, shutter speed, white balance, and a histogram among the Camera app’s controls. A histogram is a graph of tonal values, from shadows to highlights, that helps assess exposure. Photolari reported that ISO remains automatic, however, so those controls do not amount to full manual exposure control. The distinction matters most if you want to set every exposure variable yourself, particularly when shooting video.

How reviewers compare it with iPhone 17 Pro

Photolari described few overall camera-result differences from the iPhone 17 Pro in its comparison, aside from the main-camera aperture and small details. Armitage reported a stronger detail improvement than he expected against the iPhone 17 Pro. In a separate low-light comparison, he preferred the iPhone 18 Pro’s 48MP Apple ProRAW image to its 12MP Bayer RAW image. His comparisons used edited images, and they do not isolate how much of the generation-to-generation difference came from aperture, sensor, or processing.

Those accounts offer different qualitative impressions rather than a single, standardized verdict. The variable aperture is a clear compositional change; the size of any broader image-quality improvement depends on which reviewer’s comparison you consider.