Overview: Smartphone photography performance has improved significantly in recent years. To capture higher-quality photos and distant objects, flagship smartphone models are now equipped with larger-sized camera image sensors (CIS) and better telephoto lenses. Leading OEMs have different approaches to the rear camera systems in their flagship models, balancing image quality, component cost and internal design. This report analyzes the rear camera setups and costs of flagship smartphones from Apple, Samsung, Xiaomi, OPPO, and vivo. It also explores potential future trends in flagship smartphone photography systems.