Economic Observer reporter Liu Sixuan

On the early morning of September 10th Beijing time, Apple's first foldable screen phone, iPhone Duo, finally arrived.

At the press conference, Apple referred to it as the "thinnest iPhone to date". According to the official website specifications page, this device has a unfolded thickness of 5.2 millimeters, a folded thickness of 11.3 millimeters, and weighs 254 grams. However, its thickness did not meet the industry's previous prediction of 4.5 millimeters.

Nevertheless, in order to streamline space and meet current form standards, Apple has made significant reductions: the iPhone Duo has abandoned the Face ID (3D facial recognition security authentication system), independent telephoto lens, and physical SIM card slot that have been in use for nearly a decade since the iPhone X.

The iPhone Duo will be available for pre order on October 16th and will be released on October 23rd. Consumers who once had high expectations for Apple's foldable screen have to face a reality: after undergoing subtraction, this device cannot achieve any "first" parameter in this year's foldable screen competition.

Abandoned Options

At the press conference, Apple did not directly disclose the thickness of the iPhone Duo. In the past decade, the thickness of the body has almost always appeared as an independent selling point on the big screen of iPhone launch events, and this time there is only one sentence on stage: 'The thinnest iPhone to date'. This title belonged to the iPhone Air released a year ago, with a thickness of 5.6 millimeters, which is 0.4 millimeters thicker than the unfolded state of the iPhone Duo.

Among the vast iPhone family, iPhone Air is also the device with the highest similarity to iPhone Duo: in order to save internal space, both devices completely removed the physical SIM card slot. When releasing the iPhone Air, Apple gave the reason for this subtraction to obtain an "incredible lightweight body", while in the iPhone Duo, it replaced the larger battery capacity with the thickness of the card slot. The former relies on a single battery for power supply. If users want to improve the battery life, they can use the MagSafe external battery specifically designed for this model to obtain up to 65% additional power; The latter is powered by dual batteries. According to Apple's publicly available data, playing videos on the internal screen can last up to 31 hours, which is 14.8% longer than the battery life of the iPhone Air.

The independent telephoto lens is the second option that has been abandoned. The iPhone Duo has two 48 megapixel lenses at the back, which are cropped inside the main camera sensor to achieve 2x optical quality zoom and support up to 10x digital zoom.

Another subtraction is Face ID, replaced with side Touch ID (fingerprint recognition).

This is the first time that Apple's flagship phone has experienced a setback in this direction, and the 3D facial recognition problem that Android foldable screens have not been able to overcome has also stumped Apple. After unfolding, the body with a thickness of only 5.2 millimeters cannot accommodate the complete 3D structured light module composed of a dot matrix projector, a floodlight illumination device, and an infrared camera. The polarizing film and pixel wiring of the screen also absorb and distort infrared light, making the extremely difficult technology of under screen 3D even worse. In addition, the folding form also amplifies the contradiction, as the 3D module can only be installed on a single screen, and the unlocking experience of another screen will be cut off. The simplest and most effective solution is to unlock the side fingerprint while adapting to both open and close postures.

Multiple iPhone users have reported that the user experience of Face ID on previous devices was poor, with recognition errors caused by factors such as non face angles, dim lighting, hair or mask occlusion, and makeup. Users need to enter a password to turn on the device, while Touch ID can effectively improve recognition accuracy. But some users also expressed that this adjustment is not friendly to people with unclear or frequently worn fingerprints.

Parameters do not have an advantage

Looking back at the foldable screen products released by major domestic and foreign mobile phone manufacturers since January, compared with the parameters of the Android camp, iPhone Duo has almost no advantage.

Comparison of key parameters of 8 foldable screen smartphones in 2026 (illustrated by Liu Sixuan)

The iPhone Duo has a folding thickness of 11.3 millimeters, which is the thickest among the 7 dual folding devices, only slightly thinner than the Huawei Mate XT 2 with an additional screen; Weighing 254 grams, it is the heaviest in the double fold design and 53 grams heavier than the lightest one.

Not only Apple, but also Samsung Z Fold 8 Standard Edition has given up on independent telephoto lenses; But Samsung has made tiered choices within the same generation of devices, and users with needs can increase their budget to purchase Ultra.

What makes the parameter comparison more vivid is another protagonist at the same press conference - the iPhone 18 Pro Max. This model is 8.75mm thick and weighs 249 grams, lighter and thinner than the folded iPhone Duo. It also has three 48 megapixel lenses at the back, including an independent 4x telephoto lens. The starting price for the Chinese version is 10999 yuan. In other words, in order to achieve a foldable screen design, the iPhone Duo has made sacrifices in terms of imaging capabilities and weight control, and users have to pay an additional 5000 yuan for this.

Another significant difference lies in the front camera. The iPhone Duo's internal screen is not perforated, and the front camera is hidden below the screen, which makes the unfolded screen to body ratio close to 100%. However, this design did not actually result in a better visual experience. Due to the obvious creases on the inner screen, Apple chose to use a matte screen as a cover, which would affect the clarity of the front camera and require additional processing, resulting in limited lens stealth effect.

A user considering purchasing an iPhone Duo said that the most attractive aspect for her is still the iOS ecosystem, which is consistent with her reasons for choosing an iPhone every time she changes devices. "I'm used to it, it's easy to move, and it's more valuable than Android devices." As she hasn't personally experienced the device yet, she's worried about obvious creases and poor durability of the hinges.

On social media, the update that received the most positive reviews for iPhone Duo was the opening and closing transition animation. When users unfold or fold the device, the screen image naturally blurs, and the transition between different forms can achieve seamless visual connection.

(Author Liu Sixuan)