A second on that. The 500cm is a good intro to medium format shooting (the elm or elx is better suited to commercial work: noisy, heavy and best wedded to a tripod). If you take a liking to the Blad system you can expand your system, as suggested, to the holy triumvirate of the 50/80/150 or, if money is less a concern (or interest warrants) to the 50/80/120M/180). Extra backs, of course, are always a good investment - and relatively cheap.
Originally Posted by cjbecker