The Hasselblad 503CX is a medium format single-lens reflex (SLR) camera introduced by Hasselblad in 1988. It uses 120 or 220 roll film to produce 6x6 cm square images. The camera features a modular design, allowing interchangeable film backs, viewfinders, and lenses using the Hasselblad V-system bayonet mount. Notable technical improvements over its predecessor include an improved acute-matte focusing screen and built-in TTL (through-the-lens) flash metering. The 503CX is fully mechanical but requires a battery for the TTL flash metering system. It is renowned for its robust build quality and is widely used in professional studio and field photography.