The fine Silvestri 5x7 Sliding Back Adapter is made to fit their Bicam, S5 micron, and T30 series cameras. There's also a host of adapter plates, affixing to the front of this 5x7 Sliding Back Adapter, which allow trouble-free mounting to other popular view camera systems.
This device, via its viewing and imaging sides and a machined fit that allows it to slide within the rear mounting interface of the Silvestri cameras, lets you make stitched images with your digital back. An optional plate for your particular digital back is required; currently, Silvestri makes plates for Contax 645, Hasselblad, Leaf, and Mamiya 645 AFD mounts. Any digital back made to fit these systems can be used with the 5x7 Sliding Back Adapter.
Viewing from the 5x7 Sliding Back Adapter is done with a ground glass and fresnel lens combination. Some photographers may be happy just using a dark-edged loupe directly on the ground glass to compose their images, but if that's not enough there is also a proprietary bellows viewer as well as a rotating monocular reflex viewer available.
5x7 Sliding Back Adapter
D7021G Ground Glass
D7021F Fresnel Lens