Minolta RD-175
Early DSLR camera that used three CCD sensors
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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.
.jpg) 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 |
|
| Data port | 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 0.56× 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 (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]
