Quote Originally Posted by KennyMark View Post
RB finders can be used on RZ bodies, without any electronic connections between finder and body. RZ finders cannot fit RB bodies without modification.

As for other differences, three RB finders have meters. The magnifying "chimney" finder, and two different prism finders. Of course there are no connections to the lens controls on an RB.
actually I believe the non metering prism finder model 2 works with both RB and RZ models. I would like to have one of those for portrait work. sorry to keep this thread off topic :s