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The Real Reason why Spirit Only Sees Red
use_compress writes To produce a color photograph, the rover's panoramic camera takes three black-and-white images of a scene, once with a red filter, once with a green filter and once with a blue filter. Each is then tinted with the color of the filter, and the three are combined into a color image.
In assembling the Spirit photographs, however, the scientists used an image taken with an infrared filter, not the red filter (NYTimes, Free Registration Required). Some blue pigments like the cobalt in the rover color chip also emit this longer-wavelength light, which is not visible to the human eye."
How the Red Planet Came Down With the Pink Blues
If you read the whole article, you'd see that they actually used both the infrared AND the red filter for the pictures. So they had their infrared for their science as well as the red for the photos to show the public. However they mucked up in producing the photos for the public, using the infrared instead of the red. Nothing to do with science vs public interest, rather a simple mistake.
Sorry to say this, but the parent in NOT "Informative". The only sensors with 3 photosites per pixel are Foveon's. The vast majority of digital cameras has ONE photosite per pixel, and a Bayer mask (RGB filter) layered on top of it. Pixel color in the final image is then interpolated from the measured intensity of the three adjacent photosites. Yes, this means that digital cameras have higher Luma resoultion than Chroma. No, it does not matter much, because the eye is much more attracted to Luminance detail.
Almost all of the manufactured sensors are black and white; only Foveon's are 3-color, and they're expensive for the resoultion and the first generation software had color clipping problems (overexposed areas of images went abruptly to white). This has apparently been fixed.
A monochrome sensor with external filters is much more flexible than the single-duty Foveon, so I guess that's why they chose it. Also, NASA doesn't usually buy space-faring hardware off-the-shelf two weeks before launch, and this full-color sensor simply did not exist a couple of years ago.
No
A broadcast television camera (which is really pretty low-resolution, unless it's a true HTDV camera) has three CCD sensors mounted to a prisim block that splits the image into the three component colors for television (RGB). The use of three CCDs for television is necessitated by the fact that the desired result is a color image without waiting to assemble a color composite from three black and whites. Broadcast television results in images that are pretty close to 640x480 (again, prety low res).
Close, but not quite...
A Broadcast Quality camera is usually capable of recording a substantially higher resolution of image than is eventually broadcast. This allows for much better editing facilities later on - ie. Cropping and resizing of the recorded images without loss of detail in the later broadcast. Final Broadcast (in the UK at least) is around 760x575 pixels (actual broadcast lines are 625, but several are taken by the Vertical Blanking Pulse, the Frame Field Markers and Teletext data) - but the camera definately records a much higher resolution than that.
For comparison, a standard Hi-8 Domestic Hand Camera records around 540 picture lines (about 720x540), and the picture quality from this kind of camera is much lower than that needed by the broadcast editing suites to work effectively - just watch any "home video" programme (such as "You've been Framed!") for proof!
Also, expensive professional broadcast cameras use "Dichromatic Mirrors", not prisms to do colour seperation. Prismatic seperation would lead to too much signal loss and colour bleed accross the image. The first mirror directs the Red image to the appropriate sensor, and also allows enough light of all wavelengths to pass to the next mirror, where the Green image is diverted to the appropriate sensor, and again, light of all wavelengths passes to the final sensor in the camera. Blue is never explicitly seperated from the incoming image, but is instead inferred from the intensity data from the three individual sensors.
I can be very certain of both of these facts because my dad was a Video Electronics Engineer for the BBC for a number of years...
Disclaimer: I meant what I thought, not what I wrote! What? You can't read my Mind? Oh dear!