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How Spirit Takes Pictures
Some Clown writes "MSNBC has a great article on the details of the camera system on the Mars Rover titled How Sprit makes great photos. Apparently the high resolution images are all done with a 1-megapixel camera. All the money is in the CCD and Lens. The hardcore digital photographers in the crowd will probably find the article to be only a teaser on the technical specs, but the rest of us in the unwashed masses should find it interesting."
The Spirit being from NASA, I was assuming it had at least 6MP cameras. This really is pretty cool. Perhaps I'll dust my old 1MP camera off and see if I can do anything similar. If nothing else, they've proven that it's not completely worthless yet. Pretty nifty.
Damon,
http://actionPlant.com
High quality images are good for PR, but what I really want to know is how it extracts information from the environment, how this information is being used, and whether or not we found anything we didn't expect to find.
~To choose doubt as a philosophy of life is akin to choosing immobility as a means of transportation. -Yann Martel
I am not trying to be negative, I think what they are doing is great and long overdue. Can't wait till we have Rovers on other planets. But why did it cost $400 million? I've read about what Rover is and how it was built and what it does. I am sure it was expensive to build but $400 million? Does that include the cost of getting it there?
Actually, it would be fantastic if all Spirit's pictures had a finger in the bottom corner!
"NASA's Spirit Rover is providing a lesson to aspiring digital photographers: Spend your money on the lens, not the pixels."
Every good photographer will tell you the same. It still amazes me that people are willing to drop Can$.5k for a digital camera, but think you are nuts for spending the same money in a lens.
Too bad the digital cameras all come with Zooms. At the same price, a zoom lens will tend to be worse than a fixed lens. An old camera, the yashica t4 super won a great reputation for its superb fixed lens (35 mm Carl Zeiss).
I have one, and I love it. It takes the best pics I have ever seen in a P&S.
The article implies that the camera is monochrome and that filters are used to capture each color.
So, adding the images together, 1 megapixel green + 1 mp red + 1 mp blue = 3 megapixels.
Most digi-cams say that they are 3MP, but keep in mind that for any given pixel requires four elements (RGGB) to create. I believe the Spirit camera is only sensitive to light, and has interchangable filters (so it must make three passes to get full color) -- effectively tripling the "element count" of the sensor.
You quitting proves that the karma kap worked. The most annoying of the whores shut up. --CmdrTaco
to produce decent digital pictures. In fact, having very large number of pixels introduced lots of noise. The latest Sony camera - 8M pixels - is a good example. The camera simply isn't good. High level of noise, and color abberations. They've crammed too many pixels in CCD with the area too small.
OTOH, the high quality lenses and high quality post-processing of captured image are important factors in getting decent digital pictures. Yet 'unwashed masses' only understand one thing - the magic pixel number.
Maybe because spending millions of dollars on a space mission entails rigorously testing every piece of equipment which could take years before the launch? And as the article pointed out, this is not your off-the-shelf digital camera so an extra-thousand bucks will probably get you nowhere near the quality you'd otherwise expect from off-the-shelf accessories.
"Assuming the 7MB image is the raw output of the CCD, that gives 56 bits per pixel brightness. That is, each grayscale bit has 56 bits worth of information.
Not that I'm saying that's what is actually going on, just that you shouldn't expect a multi-million dollar camera to stick with 8-bits per pixel. In order to get as much information as possible (including being able to use various filters to their full effect) you would want as many bits per pixel as possible. Probably one reason the CCD elements on the camera are bigger than consumer models - more light, more differentiation between different states, and more information gained."
Duh, the maximum bit depths one would ever use would be 16bits per pixel. An ADC that could output 56bits would be too expensive and absolutely useless as the signal to noise ratio on small CCDs is just too low for an ADC of better resolution than 16bits to be of any use. You'd not gain any more signal - just more noise.