Designing a camera system requires a deep understanding of the fundamental principles of image formation and the physical characteristics of its components. Translating computer vision-based system requirements into camera system parameters is a crucial step. In this talk, we will provide a comprehensive overview of the key concepts involved in designing or specifying a camera system. We will cover the basics of image formation and the associated physics. We will discuss sensor and lens effects that impact image quality, such as diffraction, circle of confusion, and depth of field. We will also discuss application-specific requirements, including lighting conditions, frame rate and motion blur. Finally, we will present a detailed example illustrating how to translate application requirements into camera parameters, highlighting cost-performance trade-offs. Attendees will gain a thorough understanding of the key factors influencing camera system design and be able to make informed decisions when selecting or designing a camera system.