Three-CCD camera

Abeam-splitter prismassembly, with a white beam entering the front, exiting the three focal-plane faces, filtered to produce red, green and blue

A Philips type trichroic beam-splitter prism schematic, with a different color separation order than the assembly shown in the photo. The red and blue beams each undergo onetotal internal reflectionat the air gap and air–glass boundary respectively, while the other reflections are dichroic. This construction has the advantage over the above type that all 3 separated images are laterally inverted (as with a single sensor). In the first type, the blue image is not laterally inverted but the other two are.

Athree-CCD(3CCD)camerais acamerawhoseimaging systemuses three separatecharge-coupled devices(CCDs), each one receiving filtered red, green, or blue color ranges. Light coming in from thelensis split by abeam-splitter prisminto three beams, which are then filtered to produce colored light in three color ranges or "bands". The system is employed by high qualitystill cameras,telecinesystems,professional video camerasand someprosumervideo cameras.

Compared to cameras with only one CCD, three-CCD cameras generally provide superiorimage qualityby using full-framedichroic filtersto better separate the red, green and blue color bands, and better low-light performance. By separating red, green, and blue color ranges with a 1:1 pixel ratio, three-CCD cameras achieve much better precision than single-CCD cameras.

In contrast, almost all single-CCD cameras use aBayer filter,using less accurate dye filters in front of each pixel to separate the colors. Because each pixel on a single CCD sensor is covered with its own tiny color filter, a frame is necessary to keep the dye filters from leaking into adjacent pixels. The result is less light absorbed compared to a CCD without a Bayer filter. Typically there is a 2:1 ratio of green and red/blue pixels, producing less color detail.

As of 2024, no commercial 3CCD camcorders are in production due to modern Bayer sensors having improved sensitivity, higher pixel count, and better color interpolation algorithms.

Image gallery

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  A 3CCD imaging block consisting of a color separation prism of Philips type on which three CCDs are mounted
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  Three monochrome sensors and color separation prism from Sony DCR-VX1000E camera

See also

• Minolta RD-175– An early DSLR camera that used three CCD sensors
• Thin-film optics

External links

• Prism-Based Color Separation for Professional Digital Photography