DPReview: iPhone 18 Pro Manual Shutter Stops Image Stacking, Increases Noise

Technology publication DPReview has found that Apple's iPhone 18 Pro and Pro Max devices cease image stacking when the shutter speed is manually set using Pro Controls. This feature has previously been utilized to reduce noise and enhance dynamic range, particularly in low-light scenarios.

When the shutter speed is manually adjusted, the phone captures only a single frame instead of combining multiple exposures. In fully automatic mode and with manual aperture settings, the devices continue to employ image stacking. DPReview conducted tests under various lighting conditions using a tripod, observing that images captured with manual shutter speeds exhibited more noticeable noise in dim or deeply shadowed scenes compared to automatic exposure.

Beyond the inclusion of a mechanical variable aperture and Pro Controls, Apple's official announcements did not explicitly detail this trade-off between manual shutter control and computational photography processing. Users seeking granular control through manual settings may encounter unexpected image quality degradation in challenging lighting.

DPReview compared automatic exposure with manual shutter settings in static scenes, ranging from daylight to night. While differences were minimal in bright light, they became pronounced in low-light environments. Night sample shots clearly demonstrated higher noise levels in images taken with the manual shutter setting compared to those under automatic exposure.