[DigitalToday reporter Yoonseo Lee (이윤서)] Apple’s first foldable smartphone, the iPhone Duo, will be released in South Korea the next day. It is the most expensive iPhone, but some specifications, including the camera, have been assessed as falling short of the iPhone 18 Pro.

On Oct. 20 (local time), IT media outlet Engadget cited factors to review before buying the iPhone Duo, including the camera, biometric authentication method, app optimisation and accessory compatibility. It said users should closely check the differences because usage changes with the foldable display and some functions offered on previous iPhones are missing.

The biggest difference is the camera. The iPhone Duo has a main and ultra-wide rear camera but no separate telephoto camera. It can deliver 2x optical-quality zoom by cropping images from its 48-megapixel main sensor, but that differs from the iPhone 18 Pro, which has a dedicated telephoto camera. The front camera is 12 megapixels, lower than the 18 megapixels on the latest iPhones, and the main lens also lacks a variable aperture.

Biometric authentication is also different. The iPhone Duo uses Touch ID on a side button instead of Face ID. The Action button is missing, while Camera Control is retained.

App optimisation is also an early variable. Apple optimised iOS 27 for the foldable display, and when the screen is folded, apps are arranged to fit the two screens. Third-party apps, however, require updates from developers. Netflix, Zoom and Slack will provide updates in line with the release date, but some apps may, for the time being, look stretched or show black margins.

Accessory purchases add a significant extra cost. Apple’s iPhone Duo-specific case sells for 119,000 won in South Korea, and the 'Duo Folio' with a built-in stand sells for 199,000 won.

Users must buy a power adapter separately. Apple says the iPhone Duo can charge its battery to 50 percent in about 20 minutes when using a 40W Dynamic Power Adapter that supports up to 60W output. Actual charging time may vary depending on the usage environment and settings.

Apple Pencil support timing and compatibility also differ. The iPhone Duo is the first model to support the Apple Pencil, but actual use will be possible only after a software update later this year. Supported models are limited to the USB-C Apple Pencil, and the Apple Pencil (2nd generation) and Apple Pencil Pro cannot be used.

The iPhone Duo cannot be explained solely by its symbolism as Apple’s 'first foldable iPhone'. The key point of this product is that, despite its high price, it requires different choices from existing iPhones across the overall user experience, including the camera, biometric authentication, app optimisation and accessory compatibility.