The R-D1, announced by Epson in March 2004 and discontinued in 2007, was the first digital rangefinder camera. Manufactured by Cosina, which also builds the current Voigtländer and Zeiss Ikon (ZM) cameras, the R-D1 and its successor, the Epson R-D1s (mechanically identical but with a firmware upgrade), use Leica M-mount lenses or earlier Leica screw mount lenses with an adapter.
An unusual feature to note on the RD-1 is that it is a digital camera that has a mechanical shutter, despite not being a DSLR. The controls operate in the same way as film-based rangefinder cameras.
Data such as white balance, shutter speed, picture quality, and shots remaining are all displayed with servo driven indicators on a dial like a watch face (made by Epson's parent company Seiko). With the rear screen folded away, it is not obviously a digital camera.
The R-D1s's successor, the R-D1x and R-D1xG was made available from April 9th 2009 in Japan only.