Difference between revisions of "Minolta RD-175"

From Camera-wiki.org
Jump to: navigation, search
m (Rephrased a couple of sentences. Put into consistent present tense.)
Line 6: Line 6:
 
|colspan=3|images by Mikel Adell {{with permission}}
 
|colspan=3|images by Mikel Adell {{with permission}}
 
|}{{br}}
 
|}{{br}}
−
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.
+
The '''Minolta RD-175''' (also sold as the '''Agfa Actioncam''') is one of the first digital [[SLR]] cameras. When [[Minolta]] introduced this camera in 1995 it cost around $10,000 US, and was inaccessible to Minolta's usual base of amateur photographers. It was intended for professional 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 trick 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 widest effective aperture to f/6.7.
+
1 - Relay optics reduce the image size from Minolta's normal 35mm SLR lenses from 36 x 24mm to 16 x 12 mm, about 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|CCD light-sensor]].
+
2 - The light from the lens is 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 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).
+
3 - The camera has ''two'' green sensors, and one red/blue combination sensor, which is 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% by area, or ~19% by linear measure, of the size of a 35mm frame).
  
−
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.
+
4 - The three images are digitally integrated and enlarged to 1,528 x 1,146 pixels by interpolation (~1.5x). The resulting 1.75 megapixel images are stored on a PCMCIA type III hard disk card.
 +
 
 +
The handling of the camera is almost like that of other autofocus SLR cameras of the time, and the lenses for this camera are 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.
  
−
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 ==

Revision as of 17:30, 17 January 2012

3941602755_7c07292236_m.jpg 3941603635_f24e8d1903_m.jpg 3941605641_0239be0543_m.jpg
images by Mikel Adell (Image rights)


The Minolta RD-175 (also sold as the Agfa Actioncam) is one of the first digital SLR cameras. When Minolta introduced this camera in 1995 it cost around $10,000 US, and was inaccessible to Minolta's usual base of amateur photographers. It was intended for professional markets (including medical, insurance, and scientific) in which Minolta had made scant little inroads at the time.

Minolta engineers used a costly trick 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 0.5x, (doubling the effective focal length) and reducing the widest effective aperture to f/6.7.

2 - The light from the lens is 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 - The camera has two green sensors, and one red/blue combination sensor, which is 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% by area, or ~19% by linear measure, of the size of a 35mm frame).

4 - The three images are digitally integrated and enlarged to 1,528 x 1,146 pixels by interpolation (~1.5x). The resulting 1.75 megapixel images are stored on a PCMCIA type III hard disk card.

The handling of the camera is almost like that of other autofocus SLR cameras of the time, and the lenses for this camera are 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

Retrieved from "http://camera-wiki.org/index.php?title=Minolta_RD-175&oldid=122389"