The pictures below are of my giant Gowlandflex 4"x5" twin-lens camera. It isn't a reflex, as the viewing lens focuses straight onto ground-glass. Peter Gowland made a few hundred of these, having invented the beast as a tool for his own glamour photography business. It uses cut-sheet film unless one substitutes a reducing back for 120 rollfilm. Details of the background and history of these cameras can be found on Gowland's website