Aperture: The paradox of choice
The variable aperture is the most iconic feature of the iPhone 18 Pro, allowing you to physically control how much light reaches the camera sensor. A wide aperture allows more light to enter and creates a natural bokeh effect, with a shallow depth of field. In contrast, a narrow aperture widens the depth of field to keep background elements sharp, making it ideal for group shots and well-lit landscapes. Both Apple Camera and Halide support aperture control on the iPhone 18 Pro, but their approaches vary.
The iPhone’s built-in camera app lets you manually choose between four fixed values: f/1.48, f/1.8, f/2.8, and f/4.0. Or you can opt for automatic mode, which dynamically selects any value between f/1.48 and f/4.0, depending on what the algorithm deems best for the particular scene.
Foundry
Halide, on the other hand, gives you full control over the aperture. So you can adjust it and manually choose any value in the same f/1.48-4.0 range, such as f/3.33, or switch to auto. As such, Halide technically offers photographers more options than Apple’s Camera app. But more importantly, does this kind of flexibility really affect iPhone photography?
The short answer is no. The iPhone 18 Pro’s main camera sensor is too small for such small aperture settings to matter. In fact, some critics questioned Apple’s decision to incorporate a mechanical opening into the device in the first place. Many Apple Camera users will barely be able to tell the difference when jumping between adjacent preset apertures, such as f/1.48 and f/1.8. Offering users a slider with over 250 microsteps of precision in Halide is arguably overkill.
That’s not to say that Halide’s execution is completely useless. Professional photographers working in fully manual mode can lock the shutter speed and ISO (both of which affect the final exposure) to appropriate values to achieve the desired look. Having complete control over the aperture can let in just the right amount of light and perfect the overall image. However, considering the iPhone has a small sensor, it’s not as influential as having it on a professional camera, and most users will probably feel overwhelmed by its numerous options.
ISO testing
Beyond variable aperture, the iPhone 18 Pro features native support for advanced camera controls such as shutter speed and white balance. A slow shutter speed can create motion blur, while a fast one can help capture ultra-fast subjects as they move. White balance, meanwhile, allows you to control the temperature of the light, making it cooler or warmer as needed. Halide has long supported these types of adjustments, but the number of options differs.
