Camera sensitivity is a fundamental concept in imaging science and optical engineering that quantifies a camera system's ability to convert incident light (photons) into a usable electrical signal or image data. As a research area, it investigates the performance characteristics of image sensors and associated electronics under varying light conditions, focusing on factors such as quantum efficiency, noise sources, gain mechanisms, and the resulting signal-to-noise ratio. Its significance lies in determining the minimum light levels at which meaningful images can be captured, impacting the feasibility and quality of imaging applications across diverse fields, including scientific measurement, surveillance, and digital photography.