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 (MP) of resolution.^[1]: 74 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.

Minolta RD-175

Image of the Minolta RD-175
Overview
Maker	Minolta
Type	Digital SLR camera
Lens
Lens mount	A-mount
Sensor/medium
Sensor type	3 × CCD
Sensor size	1/2"
Recording medium	PC Card (Type I, II, or III)
Focusing
Focus	Automatic
Exposure/metering
Exposure modes	PASM
Flash
Flash	built-in, GN 12
Flash synchronization	1⁄90 s
Shutter
Shutter speeds	1⁄2 – 1⁄2000 s
General
Battery	1 × 6 V (2CR5, body) 1 × 7.2 V (NP-500H, back) 1 × 3 V (CR2025, clock)
Data port(s)	SCSI
Dimensions	161 mm × 128 mm × 145 mm (6.3 in × 5.0 in × 5.7 in) W × D × H
Weight	1.1 kg (2.4 lb)

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.^[2]

Technology

The camera uses Minolta A-mount lenses with a crop factor of 2.^[3]

The light entering the central 12 mm × 16 mm area of the RD-175's focal plane was compressed by 0.56x 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 (ISO) by 2+2⁄3 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 (3 × 0.3 MP) image sensors, two used for green and one for the red and blue color,^[3] reducing the sensitivity increase to about 2 stops. The only usable ISO speed was 800.^[1]: 74

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 (1528 × 1146 pixels).^[4] 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.^[3]

See also

• Telecompressor