What specific part of the iPhone's camera helps it capture more light to take better photos when it's very dark?

The iPhone's camera uses several specific integrated parts and processes to capture more light and take better photos in very dark conditions. The two primary physical components directly responsible for gathering light are the camera sensor and the lens's aperture. The camera sensor is the light-sensitive chip that converts light into electrical signals. A larger sensor, typically found in the main wide camera, can collect more photons, which are individual particles of light, because it has a greater surface area and often larger individual pixels to absorb them. The lens's aperture is the adjustable opening that lets light pass through to the sensor. A wider aperture, indicated by a smaller f-number (for example, f/1.5 compared to f/2.2), allows more light to reach the sensor in a given amount of time. This increased light intake is fundamental for low-light performance. However, in very dark conditions, simply having a larger sensor and wider aperture is not enough for truly 'better photos.' The iPhone heavily relies on computational photography, specifically a feature called Night Mode. Night Mode is not a single physical part but an advanced software process that significantly enhances the light captured by the physical sensor and lens. When activated in low light, Night Mode automatically takes a series of multiple photos (frames) over several seconds. This sequence of rapid exposures effectively extends the light-gathering period, collecting significantly more light information than a single quick shot could. The iPhone's powerful processor then analyzes these multiple frames, precisely aligns them to correct for any slight hand movement, identifies and discards blurred areas, and intelligently merges them into a single, brighter, clearer image with reduced noise and improved detail. This process results in a final image that appears far brighter and more detailed than what could be achieved from any single exposure in such dark conditions. To make this multi-frame capture possible without introducing blur, Optical Image Stabilization (OIS), or more specifically Sensor-shift Optical Image Stabilization in newer models, plays a critical role. This is a physical mechanism that constantly adjusts the lens or the sensor itself to counteract any minor hand tremors. By stabilizing the camera during the several seconds Night Mode is active, OIS ensures that the multiple exposures captured are sharp, allowing the system to gather and combine more light without motion blur, thereby directly contributing to the ability to capture more usable light for better low-light photos.