Popularized by high-end Android smartphones, periscopic zoom could make its first appearance at Apple with the iPhone 15 Pro. This technology allows a telephoto lens to be integrated into the compact body of a smartphone in order to take photos of distant subjects.
Apple has not confirmed this information, but a periscopic zoom seems obvious given the central role of the photo part in current smartphones. There’s not long to wait for confirmation as the iPhone 15 is expected to be revealed on September 12, during Apple’s “Wonderlust” event. In the meantime, here’s everything you need to know about periscopic zoom.
Why would Apple add periscope zoom to the iPhone 15 Pro?
The main reason is to provide users with better photography options. The second reason is to catch up with the competition.
Telephoto lenses are useful for photographing subjects that are a little further away, such as children on a playground or a performer on a stage. Landscape photography also benefits from the better reach that a telephoto lens offers.
The iPhone 14 Pro features a 3x telephoto lens, the equivalent of a 72mm lens on a DSLR camera. It’s useful, but it’s a far cry from the 5x zooms of Google’s Pixel 7 Pro or the 3x and 10x zooms of the Samsung Galaxy S23 Ultra. Telephoto photography is undoubtedly a weak point of the iPhone.
Google ; screenshot by Stephen Shankland/CNET
How does a periscopic zoom work?
Telephoto cameras require physically longer lens assemblies. There is no simple solution to circumvent the limitations of optics, physics and engineering.
Periscope zooms work by integrating much of this length inside the body of the phone. The external lens looks like that of a regular phone camera, but behind it is a prism or mirror that bounces light 90 degrees.
Prisms are angled blocks of transparent glass or plastic that have been used for decades in optical equipment, for example binoculars or the viewfinders of SLR cameras. High quality prisms do not degrade image quality much.
Current periscopic zoom lenses offer 5x zoom, the equivalent of a focal length of around 120mm on a traditional camera. But using just the center pixels of a high-resolution image sensor, Google’s Pixel 7 Pro can zoom 10x, or about 240mm, without any digital enlargement tricks.
How do periscope zoom lenses compare to traditional cameras?
A periscope camera offers better zoom, but don’t expect to match what seasoned photographers can do with a traditional camera and a modest telephoto lens, let alone a super telephoto lens.
There’s a reason for this limitation: periscope zoom lenses have relatively small image sensors that struggle in low light. Larger sensors provide better image quality, but they cost more, and the larger the sensor, the larger and more expensive the accompanying lens.
One of the problems with periscope cameras is that they risk supplanting mid-telephoto modules. Samsung’s Galaxy S23 Ultra solves this problem by including a conventional 3x camera with the 10x periscope. Higher resolution image sensors, like those in the Pixel 7 and iPhone 14 Pro, offer 2x modes that compensate. More unusually, Sony’s Xperia 1 V phone has a true zoom ranging continuously from 3.5x to 5.2x.
From year to year, high-end smartphones are getting closer to the zoom flexibility of traditional cameras. If the rumor of a larger main camera for the iPhone 15 Pro is true, it could facilitate other zoom options.