The development of the 500C led to multiple versions with various modifications. The 500C/M, launched in 1970, was fitted with an interchangeable focusing screen, including a prism viewfinder with a built-in exposure meter. Introduced in 1988, the 503CX was a critical advancement of the 500C/M, equipped with both a built-in flash control (OTF metering) and a very bright focusing screen. Next came the 503CXi in 1994, followed by the 501C. In 1996 came the 503CW, which received a specially made electric winder. The 501CM (1997-2005) improved upon the 501C, using the new mirror design of the 503CW. The final 503CWD was coupled with a digital CFV back, as was made possible by the modular design of Hasselblad cameras. The camera came out in 2006, the 100th birthday commemoration of Victor Hasselblad.