Wide Angle lens on Medium Format SLR

[DBY]

I just bought into the Hassy nostalgia and bought a used Hasselblad 500cm. Partly for fun, partly thinking that the SLR view through shooting lens would be handy but its occurring to me that the relatively small viewing screen might make wide angle lenses not as viewable as I was hoping. I'm curious just how wide a lens people find usable on their medium format SLRs? I already have a Fuji 690GSW - 6x9 with a 28mm equiv lens which I love but the parallax drives me crazy.

 

[cgw]

Tons of 500cm lore online.Ultra wide-angles used external optical finders that came paired with the lenses.
Then there's this...

Hasselblad SWC Review (Best Wide Angle Lens?) - Leica Blog (Matt Osborne)

Looking for the best wide angle lens film camera? Have you heard of a Hasselblad SWC? It goes wider than the Mamiya 7! (38mm vs 43mm!)

mrleica.com