The R-D1, announced by Epson in March 2004 and discontinued in 2007, was the first digital rangefinder camera. It also was the first digital mirrorless interchangeable-lens camera (MILC) 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.