The view finder here is for 4X5 only so far, but we are working on viewfinders for
      other cameras as well.

      Pay attention to the soft foldable view finder, you might find it very interesting.
It is 
      very light weight yet functional.
4X5 reflex viewer: $215
4X5 folding viewer: $60
4X5 folding viewer with carbon fiber cover: $100