Apple iPhone 18 Pro: How to use the variable aperture
Like the iPhone 17 Pro models, the new Apple iPhone 18 Pro and iPhone 18 Pro Max also feature three rear cameras: a 48MP Fusion main camera, a 48MP telephoto lens, and a 48MP ultra-wide lens. Focal lengths and resolutions are the same as their predecessors. However, the biggest innovation this year is the variable aperture of the main camera. Let’s take a closer look.
The aperture controls how much light passes through the lens and reaches the sensor of the Apple iPhone 18 Pro. If too little light reaches the sensor, the images will be blurry and/or grainy. To compensate for this, the shutter must remain open longer or Night mode must be activated. The problem is that the longer the shutter remains open or Night mode is active, the greater the likelihood of blurry images. Even still images can then lose sharpness and detail.
The solution lies in using a lens with a variable aperture, which lets in more or less light depending on the shot and thus adjusts the shutter speed. The Apple iPhone 18 Pro models can do this automatically, or you can control the process manually for more influence on the style of your images.
To achieve this, the Apple iPhone 18 Pro and iPhone 18 Pro Max replace a fixed f/1.78 aperture with a variable aperture offering four stops of range, from f/1.48 to f/4.0. This enables approximately 50 percent better low-light performance and gives photographers optical control over depth of field that the iPhone has never offered before.
Apple iPhone 18 Pro variable aperture
As mentioned previously, you can either let the variable aperture of the Apple iPhone 18 Pro be controlled automatically or take control manually.
- In the camera app, tap the button with the six dots in the bottom right corner of the user interface.
- Select “Lens Aperture” in the control panel.
- Tap one of the four circles to adjust the aperture: from left to right they are f/1.48, f/1.8, f/2.8 and finally f/4.0.
- Should you change your mind, tap the “Auto” button on the left to have the iPhone automatically control the aperture.
Experiment with different aperture settings to see how they affect your images. For example, an aperture of f/1.48 produces a shallower depth of field, while at f/4.0 a larger area of the image will be in focus.
With a variable aperture, the general rule is: the smaller the f-number (f-value), the larger the aperture opening and the more light reaches the sensor. This allows the camera to use a shorter shutter speed and simultaneously achieve a shallower depth of field under the same lighting conditions.
Conversely, the larger the f-number (aperture value), the smaller the aperture opening. This means less light reaches the sensor, but more of the subject remains in focus. The former is advantageous for isolating the subject, for example in portraits. The latter works well for landscape and group shots.
