Minolta RD-175
The Minolta RD-175 was an early digital SLR, introduced in 1995. Minolta combined an existing SLR with a three way splitter and three separate CCD image sensors, giving 0.41 megapixels of resolution. The base of the DSLR was the Minolta Maxxum 500si Super, marketed as the Dynax 500si Super in Europe and as Alpha 303si Super in Asia. Agfa produced a version of the RD-175, which retailed as the Agfa ActionCam.
The RD-175 was also notable as the first consumer digital camera to be used in a professional stop motion production, being used to create the full-motion claymation adventure video game The Neverhood.
Technology
The camera uses Minolta A-mount lenses with a crop factor of 2.The light entering the central 12 mm × 16 mm area of the RD-175's focal plane
was compressed by 0.56× relay optics behind the focal plane, similar to the optical reduction system used in the Nikon E series. The light bundled on the smaller sensor area increased the effective sensitivity by stops.
Since state of the art single-CCD resolution at the time was insufficient for Minolta, the light was split and sent to three separate 4.8 × 6.4 mm sized 768 × 494 pixel image sensors, two used for green and one for the red and blue color, reducing the sensitivity increase to about 2 stops. The only usable ISO speed was 800.
Images were stored on an internal 128 MB PCMCIA hard drive. The output of the three sensors were combined digitally when imported to a computer and interpolated to the final size of 1.8 MP. On its original release, the bundled software was compatible only with Macintosh OS. Depending on the computer, importing and processing a single image could take from 50 to 108 seconds.