以下是翻译内容： iPhone 18 Pro在其主摄像头镜头上引入了一项重大但影响细微的更新：一个可变光圈。这项新硬件拥有六片叶片，每片叶片都只有头发丝般细，使其能够像传统相机的光圈一样开合。这与大多数手机摄像头不同，后者通常使用固定光圈以简化设计并最大限度地捕捉光线。 然而，这位测评人对这种可变光圈的实际效用表示怀疑。尽管传统相机使用光圈来控制景深（DoF）并创造散景效果（模糊的背景），但在智能手机上，这种效果有所不同。由于其更小的传感器和镜头，智能手机上的f/1.8光圈产生的景深更类似于全画幅相机上的f/5.6光圈，这意味着场景中已有更多区域处于对焦状态。因此，在微型手机镜头上操控光圈对背景虚化效果影响微乎其微，特别是与模拟这种效果的软件驱动人像模式相比。 新光圈的主要优势在于改善了弱光性能，它可以开到f/1.48（比之前的f/1.8更亮）。更宽的光圈让更多光线进入传感器，使系统能够使用更低的ISO，以获得略微更清晰的图像，而无需依赖夜间模式。尽管细节上的提升被描述为微不足道，但它能缩短夜间模式的拍摄时间并提高快门速度，这对于拍摄移动物体是有利的。光圈还会自动调整，通常保持在f/1.8，但在弱光环境下会开到f/1.48，并在检测到文本（如笔记）时缩小到f/4以保持清晰。测评人指出，三星、索尼和小米等其他制造商此前已在其手机中放弃了可变光圈技术，暗示了其实现或感知益处可能存在潜在挑战。 除了光圈之外，iPhone 18 Pro还带来了其他显著的摄像头增强功能。用户首次可以在相机应用内手动调整快门速度、焦点和白平衡，尽管ISO仍然不可调，且屏幕上的控件很小。光圈缩小到f/4的能力，使得由于光圈叶片可以产生独特的“星芒”（sun stars）效果，这是测评人很喜欢的一个功能。 iOS 27中的新AI编辑工具，例如“重新构图与扩展”（Reframe and Extend），允许用户在照片拍摄后，利用AI修改构图并填补空白。测评人对这些工具表达了强烈的伦理担忧，称其为“噩梦燃料”，因为它们能够巧妙地改变摄影现实。为了解决这些担忧，Apple正引入Synth ID来标记AI编辑过的照片，并在18 Pro上推出新的“参考图像”（Reference Image）功能。此模式会在照片从传感器输出时，以像素级加密签名，实质上创建了一个存储在Apple私人云服务器上的“数字底片”，从而允许验证原始未编辑图像。尽管目前有些笨拙，但它被认为是解决真实性问题的强大方案，对新闻摄影师来说可能很有用。 其他更新包括摄影风格中新增的纹理选项（例如胶片颗粒，适用于所有兼容的iPhone，而不仅仅是18 Pro），以及视频方面更新的AI驱动焦点跟踪功能，即使拍摄对象暂时离开画面也能持续跟踪。18 Pro还配备了A20 Pro芯片组、改进的散热性能、更快的有线充电以及增强的电池续航能力，特别是Pro Max机型。灵动岛现在最多可以显示三项实时活动。 总而言之，测评人发现可变光圈功能，尽管技术上很复杂，但并没有显著提升使用iPhone 18 Pro相机“乐趣”，他更喜欢使用4倍长焦镜头来获得这种乐趣。尽管其优势对普通用户来说可能微乎其微，但景深控制的灵活性或新的胶片颗粒效果可能会吸引小众用户。

The iPhone 18 Pro introduces a significant, though subtly impactful, update to its main camera lens: a moving aperture. This new hardware features six blades, each the width of a human hair, allowing it to open and close much like the iris of a traditional camera. This differs from most phone cameras, which typically use fixed apertures for simplicity and to maximize light capture. However, the reviewer expresses skepticism about the practical utility of this variable aperture. While traditional cameras use aperture to control depth of field (DoF) and create bokeh (blurred backgrounds), the effect is different on smartphones. Due to their smaller sensors and lenses, an f/1.8 aperture on a smartphone produces a DoF more akin to an f/5.6 on a full-frame camera, meaning more of the scene is already in focus. Consequently, manipulating the aperture on a tiny phone lens has a minimal impact on background blur, especially compared to the software-driven Portrait Mode, which mimics this effect. The primary benefit of the new aperture, which can open as wide as f/1.48 (brighter than the previous f/1.8), lies in improved low-light performance. A wider aperture allows more light to reach the sensor, enabling the system to use a lower ISO for slightly crisper images without relying on Night Mode. While the gains in detail are described as minor, it can lead to shorter Night Mode capture times and faster shutter speeds, which is advantageous for photographing moving subjects. The aperture also adjusts automatically, typically sticking to f/1.8 but opening to f/1.48 in low light, and narrowing to f/4 when detecting text (like notes) to keep it sharp. The reviewer notes that other manufacturers like Samsung, Sony, and Xiaomi have previously abandoned variable aperture technology in their phones, hinting at potential challenges with its implementation or perceived benefits. Beyond the aperture, the iPhone 18 Pro brings other notable camera enhancements. For the first time, users can manually adjust shutter speed, focus, and white balance directly within the camera app, although ISO remains non-adjustable and the on-screen controls are small. The ability to stop down to f/4 allows for the creation of distinct "sun stars" effects due to the aperture blades, a feature the reviewer enjoyed. New AI editing tools in iOS 27, such as "Reframe and Extend," allow users to modify framing and fill in gaps using AI after a photo is taken. The reviewer expresses strong ethical concerns about these tools, deeming them "nightmare fuel" due to their ability to subtly alter photographic reality. To address these concerns, Apple is introducing Synth ID to tag AI-edited photos and a new "Reference Image" feature on the 18 Pro. This mode cryptographically signs photos at the pixel level as they come off the sensor, essentially creating a "digital negative" stored on Apple's private cloud server, allowing verification of the original unedited image. While currently clunky, it's presented as a robust solution for authenticity, potentially useful for photojournalists. Other updates include new texture options (like film grain) for photographic styles (available on all compatible iPhones, not just the 18 Pro), and updated AI-powered focus tracking for video, which is persistent even if subjects temporarily leave the frame. The 18 Pro also features an A20 Pro chipset, improved thermals, faster wired charging, and enhanced battery life, particularly for the Pro Max. The Dynamic Island can now display up to three live activities. In conclusion, the reviewer found the moving aperture feature, despite its technical sophistication, didn't significantly enhance the "fun" of using the iPhone 18 Pro's camera, preferring the 4x telephoto lens for that. While its benefits might be minor for the average user, the flexibility in depth of field or the new film grain effects could appeal to a niche audience.