Apple has introduced a mechanical aperture for the first time in an iPhone camera, a feature now available in the iPhone 18 Pro and Pro Max models. This hardware-based addition allows users limited manual control over exposure and depth of field, which are key elements in photography that determine how much light enters the camera and how much of the image is in focus. This feature is not only a first for Apple, but also relatively rare in the smartphone industry. While most smartphones use fixed-lens apertures, Huawei has incorporated mechanical apertures in several of its flagship models, including the Pura 80 Ultra. The iPhone 18 Pro series now joins this small group of devices with this kind of hardware innovation. Previously, all iPhones, and most smartphones, used a fixed aperture, which means the opening that allows light into the camera couldn’t be adjusted. For example, the iPhone 17 Pro had an f/1.78 aperture. The iPhone 18 Pro series changes this with a mechanical aperture that includes six blades, each thinner than a human hair, made from a polymer composite. This new aperture can open as wide as f/1.48 and close down to f/4, allowing more light in than previous iPhone models. Apple highlights that this mechanical aperture is especially useful for indoor portraits and astrophotography. Beyond the increased light intake, it also offers better exposure control and image sharpness. When the aperture is closed down from f/1.48 to f/4, less light reaches the camera sensor, which is helpful in bright conditions. This allows for slower shutter speeds, which are essential for smooth video recording and long exposure effects. A smaller aperture also tends to produce sharper images by utilizing the central, sharpest part of the lens and reducing softness and distortion that can occur with wider apertures.