Difference between revisions of "Minolta RD-175"
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| − | The '''Minolta RD-175''' (also sold as the '''Agfa Actioncam''') was one of the first digital [[SLR]] cameras. When [[Minolta]] introduced this camera in 1995 it cost around $10,000 US, inaccessible to Minolta's usual base of | + | The '''Minolta RD-175''' (also sold as the '''Agfa Actioncam''') was one of the first digital [[SLR]] cameras. When [[Minolta]] introduced this camera in 1995 it cost around $10,000 US, inaccessible to Minolta's usual base of amateur and enthusiast photographers, intended for professional business markets (including medical, insurance, and scientific) in which Minolta had made scant little inroads at the time. |
Minolta engineers used a costly tricks to get acceptable colour pictures in 1.75 [[megapixel|mega-pixel]] resolution: | Minolta engineers used a costly tricks to get acceptable colour pictures in 1.75 [[megapixel|mega-pixel]] resolution: | ||
| − | 1 - Relay optics reduce the image size from Minolta's normal 35mm SLR lenses from 36 x 24mm to 16 x 12 mm, about 1/2 or ~0.5x, (doubling the effective focal length) and reducing the | + | 1 - Relay optics reduce the image size from Minolta's normal 35mm SLR lenses from 36 x 24mm to 16 x 12 mm, about 1/2 or ~0.5x, (doubling the effective focal length) and reducing the widest effective aperture to f/6.7. |
| − | 2 - The light which got through the lens was split using a dichroic prism block | + | 2 - The light which got through the lens was split using a dichroic prism block into the required colour components for each sensor. Each part was projected onto its own [[CCD|CCD light-sensor]]. |
| − | 3 - They used two green sensors, and one red/blue combination sensor, which was striped using | + | 3 - They used two green sensors, and one red/blue combination sensor, which was striped using microscopic filter elements. This made the camera back huge compared to film SLRs. Each CCD has a resolution of 768 x 494 pixels on 6.4 x 4.8 mm chips (~3.6% area, or ~19% linear of the size of 35mm film). |
| − | 4 - | + | 4 - The three images were digitally integrated and interpolated out to 1,528 x 1,146 pixels, ~1.5x. The resulting 1.75 megapixel images were stored on a PCMCIA type III hard disk card. |
| − | The handling of the camera was almost like that of other autofocus SLR cameras of the time, and the lenses for this camera were simply the same as | + | The handling of the camera was almost like that of other autofocus SLR cameras of the time, and the lenses for this camera were simply the same as those for Minolta's Alpha/Dynax/Maxxum film SLR camera bodies. The picture quality, once praised, is far behind that of [[Konica Minolta]]'s later digital SLRs using Sony's single-chip 6 mega-pixel resolution sensor. |
== Links == | == Links == | ||
* [http://www.epi-centre.com/reports/9605cs.html RD-175/Agfa Actioncam review] by John Henshall | * [http://www.epi-centre.com/reports/9605cs.html RD-175/Agfa Actioncam review] by John Henshall | ||
* [http://www.nikonweb.com/actioncam/ Agfa Actioncam] on Jarle Aasland's [http://www.nikonweb.com/ NikonWeb.com site] | * [http://www.nikonweb.com/actioncam/ Agfa Actioncam] on Jarle Aasland's [http://www.nikonweb.com/ NikonWeb.com site] | ||
| − | * [http://www.butkus.org/chinon/minolta/minolta_rd-175/minolta_rd-175.htm Minolta RD-175 English 6 page PDF quick guide] @ www.orphancameras.com | + | * [http://www.butkus.org/chinon/minolta/minolta_rd-175/minolta_rd-175.htm Minolta RD-175 English 6 page PDF quick guide] @ Mike Butkus' www.orphancameras.com |
* [http://www.pbase.com/cameras/minolta/dimage_rd175 Example images] at Pbase.com | * [http://www.pbase.com/cameras/minolta/dimage_rd175 Example images] at Pbase.com | ||
Revision as of 21:57, 4 March 2009
The Minolta RD-175 (also sold as the Agfa Actioncam) was one of the first digital SLR cameras. When Minolta introduced this camera in 1995 it cost around $10,000 US, inaccessible to Minolta's usual base of amateur and enthusiast photographers, intended for professional business markets (including medical, insurance, and scientific) in which Minolta had made scant little inroads at the time.
Minolta engineers used a costly tricks to get acceptable colour pictures in 1.75 mega-pixel resolution:
1 - Relay optics reduce the image size from Minolta's normal 35mm SLR lenses from 36 x 24mm to 16 x 12 mm, about 1/2 or ~0.5x, (doubling the effective focal length) and reducing the widest effective aperture to f/6.7.
2 - The light which got through the lens was split using a dichroic prism block into the required colour components for each sensor. Each part was projected onto its own CCD light-sensor.
3 - They used two green sensors, and one red/blue combination sensor, which was striped using microscopic filter elements. This made the camera back huge compared to film SLRs. Each CCD has a resolution of 768 x 494 pixels on 6.4 x 4.8 mm chips (~3.6% area, or ~19% linear of the size of 35mm film).
4 - The three images were digitally integrated and interpolated out to 1,528 x 1,146 pixels, ~1.5x. The resulting 1.75 megapixel images were stored on a PCMCIA type III hard disk card.
The handling of the camera was almost like that of other autofocus SLR cameras of the time, and the lenses for this camera were simply the same as those for Minolta's Alpha/Dynax/Maxxum film SLR camera bodies. The picture quality, once praised, is far behind that of Konica Minolta's later digital SLRs using Sony's single-chip 6 mega-pixel resolution sensor.
Links
- RD-175/Agfa Actioncam review by John Henshall
- Agfa Actioncam on Jarle Aasland's NikonWeb.com site
- Minolta RD-175 English 6 page PDF quick guide @ Mike Butkus' www.orphancameras.com
- Example images at Pbase.com
