What prism is this?
What viewfinder prism is the one featured on this Hasselblad camera? And is its functionality specific to a particular V-System Hasselblad? I have a 501CM and am thinking of getting a 45 degree viewfinder.
Ted,it looks like a PME 45-very,very expensive-$1000 +.Kiev make 45 degree prisms that fit hasselblads,you can get these for less than $50,the Kievs meters are nowhere near as accurate as Hasselblads-but you may meter handheld anyway.You can even get older model Hasselblad brand,non metered,45's for around $50 too.
Looks to be a PME-45;
Hasselbladhistorical has a manual for the PME90, which I think, has similar functionality.
In general, I like the 45 deg. prisms a lot, I have a PME51 which is an older metered "PM" type prism.
I'm pretty sure it is a version of the PME51. According to a 1957 Hasselblad catalog I haven't had the heart to discard, it has the same design as the PM5 but has a center-weighted TTL meter with a silicon cell, ISO range 25-6400, scale illumination by a red LED, push button start and auto shut-off after 10s. Takes a 6V type PX28 or equivalent battery. Possibly it was pre-dated by as mentioned a PME45.