[...] Having said that i'm not sure what some of the differences are between certain models. The model i'm considering is the 500 series. What is the difference between 500, 501 or 503?
Hello!
500 C, C/M?
501 C or CM?
503 CX, CXi or CW?
The (main) differences between all Hasselblad V-System models is listed in the
"concise tabulated history of Hasselblad camera models" you can find
here.
Basically, the 500 C and C/M models are the 'archetypical' Hasselblads. Fully mechanical.
The 503 models added TTL-OTF flash control (using the appropriate flash units and adapters), with the 503 CXi (note that little "i"!) and the 503 CW also taking an add-on motor winder.
The 501 models were meant to be a "budget" (still expensive) choice, offered along with the 503 CW model. The 501 C and CM differ in that the later (CM) has a larger non-vignetting mirror. The only other non-motorized 500-series camera that has that longer mirror is the 503 CW.
I'll explain what that mirror thing is about:
The 500 cameras had a mirror that was made too short, and thus created a slight viewfinder vignetting (the top of the image was cut off by the mirror. But only in the viewfinder. Not on film!), but only when when using longer lenses or when adding extension between the lens and the camera.
The mirror was made too short on purpose, because of the 80 mm lens which protruded just a bit too far into the body, and a large-enough mirror would hit the lens when moving up or down.
Starting with the 503 CW (in the non-motorized 500-series line; the focal plane shutter 2000-series cameras had it first, some 20 years before the 503 CW. In the 500-series the 500 ELX was way ahead of the 503 CW too), the mirror mechanism was changed so that the mirror would move backwards as well as up, avoiding the lens, and making a larger mirror possible. The 501 CM was the only other camera in the non-motorized 500-series that has this mechanism.
That mechanism is now called the Gliding Mirror System. Before the 503 CW it didn't have a name.