When shooting in very low light with a new iPhone, what specific computational photography process helps capture more detail and reduce noise, even before you start editing?

When shooting in very low light with a new iPhone, the specific computational photography process that helps capture more detail and reduce noise, even before you start editing, is Night Mode. Night Mode automatically activates in extremely dim conditions. This process begins by capturing a rapid sequence of multiple images, or frames, over a few seconds. These frames are not identical; they typically include a mix of short-exposure frames to capture sharp detail in brighter areas and longer-exposure frames to gather more light information from darker regions, as a single long exposure often results in motion blur from camera shake and increased digital noise. Once these frames are captured, the iPhone's powerful chip, using its Neural Engine for machine learning, performs sophisticated image alignment. This step precisely registers and aligns all the individual frames, compensating for any slight hand movement during the capture period, which is crucial to prevent ghosting or blurry artifacts when merging. After alignment, the aligned frames are then stacked and merged. This is a core computational photography technique where information from each frame is combined; by averaging the pixel data across multiple frames, random noise, which is inconsistent from frame to frame, is significantly reduced while consistent scene details are reinforced and preserved. This effectively increases the signal-to-noise ratio, meaning the actual image information becomes much stronger relative to unwanted noise. Following the merging, advanced AI-powered denoising algorithms are applied. These algorithms intelligently analyze the merged image, distinguishing between genuine image detail and remaining digital noise, then selectively smooth out the noise while preserving fine textures and edges. Finally, local tone mapping and color correction are performed. Tone mapping optimizes the dynamic range, ensuring that both the very bright and very dark areas of the scene contain visible detail rather than being completely blown out or crushed to black, and ensures natural-looking colors and contrasts, producing a final photograph that is brighter, sharper, and significantly less noisy than what a single, traditional exposure could achieve in the same low-light conditions, all before the user sees the image.