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The Real Reason why Spirit Only Sees Red

CmdrTaco posted more than 10 years ago | from the now-thats-interesting dept.

Space 273

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."

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Primeiro borne para Lula! (-1)

Adolf Hitroll (562418) | more than 10 years ago | (#8236369)

Primeiro borne para Lula!
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Re:Primeiro borne para Lula! (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8236559)

I'm sorry to say this, but chief of staff Ernst Roehm was plotting my assassination!

Re:Primeiro borne para Lula! (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8236584)

tee hee. he said "ass ass" ination.

Re:Primeiro borne para Lula! (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8236637)

u r so k3wl .Did your dad buy you teh domane? Its really graet!!!

I JUST EJACULATED ALL OVER MY KITTENS! (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8236376)

Now they are licking my cum off of each other!

Was in New Scientist a week or so ago (5, Insightful)

Space cowboy (13680) | more than 10 years ago | (#8236379)

The reason being that the science gets better results using th e IR filter than if the red filter were used... At the moment, despite great public interest, the science is more important... that IS what it's there for....

Simon

Re:Was in New Scientist a week or so ago (4, Informative)

SpinyManiac (542071) | more than 10 years ago | (#8236477)

Not just that, using a B/W camera allows them to use any filter they like.

They have at least 14 filters, taking 14 cameras would be impossible.

Info here. [nasa.gov]

Re:Was in New Scientist a week or so ago (0)

Anonymous Coward | more than 10 years ago | (#8236488)

Hmm, perhaps. But who is paying for it to get up there? Maybe theyd be more interested in some pretty pictures for their dollar.

Re:Was in New Scientist a week or so ago (5, Informative)

mcbevin (450303) | more than 10 years ago | (#8236503)

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.

From the 2/6 transcript, SCO v IBM (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8236541)

Directly from the transcript - things don't seem to be going to well for IBM, do they, Linux kooks?

THE COURT - Mr Marriott, my question for you is, do you acknowledge or not acknowledge that S.C.O. is in substantial compliance with the previous order?

MR MARRIOTT - Well, that is a very hard question, your Honor -

THE COURT - Mr Marriott, IBM has had ample time to analyze S.C.O.'s response - are you telling me that IBM has again failed to do its homework?

Re:From the 2/6 transcript, SCO v IBM (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8236621)

Hey, that's just a total lie. Here's the real transcript:

THE COURT: Mr. Marriott, my question for you is, do you acknowledge or not acknowledge that S.C.O. is in substantial compliance with the previous order?

MR. MARRIOTT: Well, that is a very hard question, Your Honor. We were provided with a lot of documents and we were given certainly a lot more specificity than we had been provided previously.

The difficulty is that since in our judgment without getting to the merits, but in our judgment the question here is whether the code they say we have dumped into Linux can be linked to Unix System Five. They have a different view. We won't argue the merits of that. Certainly we are entitled to discovery as to whether that is the case. I would refer Your Honor to our interrogatory numbers one, two, four, six, nine and 13.

In one we ask for confidential information misused. In two we ask for the nature and the source of the rights. In four we ask for the manner of misuse. In six the origin of the code and the products upon which it is based. I mean, the list goes on, Your Honor. One of which, in fact, 12 asks specifically whether the code was derived from Unix System Five. So whether or not we have the same view on the merits as S.C.O. as to the contracts, which clearly we do not, certainly we are entitled to discovery as to our understanding of the way the contract works. We have clearly asked for that. This is a case that to my mind is about whether Unix System Five in one fashion or another, either directly or because some derivative of it has been dumped into Linux has been adequately provided and we don't have that.

To be asked when they have given us a lot, Your Honor, it is --

THE COURT: Maybe that is a determination for me and not for you.

Do you have anything else on this?

MR. MARRIOTT: I do not, Your Honor.

THE COURT: Thank you.

I will take that under advisement, but let's go forward now on the issue of S.C.O. 's motion for discovery from I.B.M.

From here [groklaw.net]

Re:Was in New Scientist a week or so ago (2, Funny)

AndroidCat (229562) | more than 10 years ago | (#8236548)

Was in my sig a week ago too. :^P Nasa denies 'sexing up' mars images [ananova.com] which references the New Scientist story.

Will Slashdot cover oxygen discovered on extra-solar planet Osiris next week? Stay tuned!

Cue a thousand alien-watcher website updates.. (5, Funny)

Channard (693317) | more than 10 years ago | (#8236384)

'Aha! So that's why they don't see little green men...' - at last, the dream of aliens living on Mars is alive again.

Re:Cue a thousand alien-watcher website updates.. (1, Funny)

martingunnarsson (590268) | more than 10 years ago | (#8236451)

I for one welcome our new red martian overlords.

Re:Cue a thousand alien-watcher website updates.. (0)

Anonymous Coward | more than 10 years ago | (#8236533)

That was really cheap. Thanks god you won't get karma for it. But image someone will mod you down from +5 later. HAHAHAHAHA!

Re:Cue a thousand alien-watcher website updates.. (1)

AndroidCat (229562) | more than 10 years ago | (#8236613)

Whacked colours are the least of it. A nice article here Conspiracy theorists stake out Red Planet [thestar.com]
What few remember is that, in the late 1950s, Russian astronomer Iosif Shklovskii floated the idea of civilizations on Mars, but he did it based on actual scientific data.
(Spoiler warning) Later data proved him wrong.

Re:Cue a thousand alien-watcher scientologists (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8236865)

cisar.org/survey/up.htm
why did the USA pressure europe to accept the cult of scientology?

prepare the servers for a nytimes-dotting... (5, Funny)

mobiux (118006) | more than 10 years ago | (#8236389)

They mention slashdot.org by name.

Could this be some sort of revenge?

Re:prepare the servers for a nytimes-dotting... (4, Interesting)

arcanumas (646807) | more than 10 years ago | (#8236424)

If they wanted to take their revange they would have made it a link. Now, it is just text and most people don't like copy-pasting.
But they mention that "As Mars buffs have pointed out in recent weeks on Web sites like Slashdot.org" , i wonder if they read Slashdot because they like it or just to see why an ungodly amount of refferer logs says: slashdot.org

Re:prepare the servers for a nytimes-dotting... (5, Funny)

Asprin (545477) | more than 10 years ago | (#8236427)


Quick! Put up the free registration page!

Re:prepare the servers for a nytimes-dotting... (5, Funny)

lukewarmfusion (726141) | more than 10 years ago | (#8236465)

Then NYTimes will have to link to the Google cache, someone will copy and paste the unformatted text on their site anyway, and we'll see a plagiarizing reporter trying to karma whore in order to get his job back.

Of course you know.... this means war.

Re:prepare the servers for a nytimes-dotting... (1, Funny)

Asprin (545477) | more than 10 years ago | (#8236509)


Lieutennant, release the FIRST POSTERS!

Re:prepare the servers for a nytimes-dotting... (1)

AdamTheBastard (532937) | more than 10 years ago | (#8236524)

Someone think of a CowboyNeal poll option on the double!

THERE ARE NO PHOTOS! I TELL YOU! (-1, Troll)

freerecords (750663) | more than 10 years ago | (#8236391)

There are no photos! It is all a government conspiracy... There is no other life... There is no color red..

Oh and SCO are totally right in everything they say ;)..

HRC (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8236393)

First Post

Why b/w & filter? (5, Interesting)

Lolaine (262966) | more than 10 years ago | (#8236394)

Can anyone explain why 3 separate B/W images are taken? If it is because of bandwidth... 3 grayscale images weights (more or less) like one color image ... so why B/W and filters?

Re:Why b/w & filter? (1, Informative)

EyeSavant (725627) | more than 10 years ago | (#8236419)

I would guess that it is to do with the cost, and weight of the high resolution camera.

They can get much higher resolution in grayscale, so they get better pictures but slower, with cheaper and lighter kit.

I would guess the bandwidth is the same, or almost the same.

Re:Why b/w & filter? (4, Informative)

anubi (640541) | more than 10 years ago | (#8236422)

I understand its because its a heckuva lot easier to build high resolution cameras as monochrome, as you can place the pixels immediately adjacent to each other and not concern yourself with placement of color filter masks.

Also, having external color filter masks which can be rotated into place means we are no longer limited in vision to just the visible spectrum we see, but we can see anything the raw silicon sensor allows, meaning we can also view the infrared to ultraviolet, and let us assign "pseudo color" as we see fit.

Re:Why b/w & filter? (1, Informative)

Asprin (545477) | more than 10 years ago | (#8236495)


This might be the same thing you're saying, but I would guess that it's because in a color camera, you have three different color sensors per pixel that are arranged in a bundle like the pixels on your TV set. This causes a certain amount of chromatic distortion because each color really only sees one-third of the whole picture. However, if you use a monochrome camera and filters, each pixel gets completely recorded in each color and you can later stack the color planes on top of each other and blend them which gives you better color and resolution with a LOT less distortion.

...but that's just a guess.

Re:Why b/w & filter? (5, Informative)

herko_cl (533936) | more than 10 years ago | (#8236821)

Sorry to say this, but the parent in NOT "Informative". The only sensors with 3 photosites per pixel are Foveon's [foveon.com] . 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.

Re:Why b/w & filter? (4, Informative)

mhollis (727905) | more than 10 years ago | (#8236618)

Essentially, that's what all professional cameras do.

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).

The MER images are stills. As such, there is time to put together a composite of the separate components taken with the filters. The data desired is high resolution and each of the composite images (irRGB) yields different information. Additionally, JPL is not lacking computer time for assembling the result of the component images. We're not talking live video feeds here.

I note that there has been some discussion of weight here. That is not a factor in this case. Each of the filters, together with the CCD and the precise movement motor probably weighs about the same as a three CCD system, but in this case, it is one CCD, so any defects can be known and programmed around so there are no trade-offs. The issues JPL/NASA are dealing with have more to do with the size of the data sets and the available time in which the MERs can communicate with Earth.

Re:Why b/w & filter? (0)

Anonymous Coward | more than 10 years ago | (#8236429)

Then you only need a B/W sensor on the rover, which is much simpler than a color sensor. Also, you can use a higher quality B/W sensor.

Re:Why b/w & filter? (1)

mefus (34481) | more than 10 years ago | (#8236446)

Can anyone explain why 3 separate B/W images are taken?

Resolution (not bandwidth.) A color camera would deliver one third the number of pixels per image that a grayscale image does.

Re:Why b/w & filter? (3, Informative)

richie2000 (159732) | more than 10 years ago | (#8236466)

My guess is that it's easier to get more resolution out of the camera this way. You can use the full resolution for every colour instead of having 4 sensors (RGB + IR) on-chip per pixel. More on the MER cameras here [space.com]

I can still remember using a NewTek DigiView digitizer with a b/w video camera and filters so I guess the Alzheimer hasn't gotten to me yet. :-)

Re:Why b/w & filter? (-1, Offtopic)

A55M0NKEY (554964) | more than 10 years ago | (#8236593)

I wonder if I can use an old cheap B&W web-cam to make IR goggles like the Fire Dept has...

Re:Why b/w & filter? (1)

SlightOverdose (689181) | more than 10 years ago | (#8236469)

The rover just doesn't have a color camera. Everything on the rover had to be justified, and a color camera would have no real value as they can fake it with the filters.

Re:Why b/w & filter? (2, Insightful)

MCZapf (218870) | more than 10 years ago | (#8236708)

Fake it?? It's still a real picture! The landscape isn't moving, so it doesn't really matter if the camera captures each color in succession, rather than all at once, as in most cameras. It's a tradeoff; it takes longer to capture all the data, but you get a higher resolution full-color image as a result.

Re:Why b/w & filter? (2, Informative)

MartyC (85307) | more than 10 years ago | (#8236473)

The imaging system used is a monochromatic camera, because they are simpler to operate and calibrate. The science teams aren't particularly interested in colour photography, the filters are there to narrow down the response range of the detector to provide some useful information on the surface properties of the things they image, as different minerals reflect/absorb/scatter light differently. By using filters of known transmission characteristics you can infer things about the soil and rocks around you. A colour CCD like you have in your average digital camera wouldn't be able to do this.
As a side-effect you can colorise and recombine the images to approximate a colour picture as you might see if you were stood there yourself. Some NASA PR guys stitch these together while the science team go to work on the black and white stuff.

Re:Why b/w & filter? (0)

Anonymous Coward | more than 10 years ago | (#8236478)

This has been discussed to death in several previous threads about the lander. Check out How Spirit Takes Pictures [slashdot.org] . Which more or less makes this article a dupe, but hey it's Taco, so I expect nothing less. Must be a slow news for nerds day.

Re:Why b/w & filter? (4, Informative)

EvilTwinSkippy (112490) | more than 10 years ago | (#8236500)

They are sending the raw picture uncompressed. Well, they might use a run-length encoding, but the result is a lossless image. JPEG is so much smaller because it really cuts corners, and exploits the fact that our eyes are more sensitive to contrast than the magnetude difference between colors.

With scientific imaging, OTOH, you want the raw information coming off the CCD. They are interested in everything, not just what the human eye can see.

So, with lossless encoded, 3 greyscale images actually come out to be the same size as a color image. (Look at a color TIFF for example.) The advantage of the B/W and filter approach is that you need only one capture device. On a spacecraft there are many design advantages. Besides, you now have 3 copies of the same image. You never know when one copy will pick something up that the others missed.

Re: Compression (2, Informative)

the real darkskye (723822) | more than 10 years ago | (#8236561)

To blockquoth the source [cornell.edu]
When each twin-lens CCD (charge-coupled device) camera takes pictures, the electronic images will be sent to the rover's onboard computer for a number of onboard image processing steps, including compression, before the data are sent to Earth


Unfortuantly I can't find any references as to the loss{y|less}ness of the compression used

Re:Why b/w & filter? (4, Informative)

mdielmann (514750) | more than 10 years ago | (#8236876)

Note also that color CCDs aren't actually color, but a B/W CCD (There really isn't a such thing as a color CCD) with 3 different color filters applied pixel-by-pixel. This has the drawback of interpolation, and the collection of 1/3 of the raw data. The only way to get true color is to use either 3 (or more, depending on what you want to see) CCDs with an image splitter so they all see the same thing, or a series of filters, with each color taken in turn. Guess which one is smaller.

Versatility (4, Insightful)

Detritus (11846) | more than 10 years ago | (#8236525)

Instead of being limited to some fixed approximations of red, green, and blue, they can use a larger set of filters that are tailored for various science objectives.

The human eye's color vision is a poor scientific instrument. It can be easily fooled.

Re:Why b/w & filter? (1)

aauu (46157) | more than 10 years ago | (#8236649)

Same difference .E.g. three 8 bit images take the same bandwidth as one 24 bit color image. Additionally, they may only want a b&w image in ultraviolet or infrared. This case would only take 1/3 the bandwidth. The link speed is on the order of 10 to 1000 bits per second except thru the mars orbiters. Maximum information for bandwitdh is optimized, not pretty tourist pictures with a limited drugstore camera.

Re:Why b/w & filter? (2, Informative)

SmackCrackandPot (641205) | more than 10 years ago | (#8236671)

We're working with an industrial use colour camera sensor - basically your typical digital CCD array with the rest of the camera removed (no auto-focus, white-balance, flash etc...) Pixels are arranged in a groups of 2x2 (Red, Green, Green, Blue). In bright scenes, the signal strength can bleed between the individual colour cells, which is extremely tricky to compensate for. However, If you take individual frames of each light wavelength that you are interested in using a monochrome camera, by using colour filters of your choice, you not only get a higher resolution, but you also know exactly the sensitivity of the CCD for that frequency.

Also, the human vision system also performs white-balancing on it's own. If you've ever looked through a window at dusk in Winter, you'll notice that outside will appear with a blue tint, while if you're outside, all the rooms inside will appear to have an orange/yellow tint. Your eyes are trying to get the average colour to white.

Science, not reality TV (3, Funny)

kinnell (607819) | more than 10 years ago | (#8236395)

It's a good job the pictures aren't coming back with a blue tint, or lynch mobs would be turning up at NASA HQ.

Re:Science, not reality TV (1)

Vreejack (68778) | more than 10 years ago | (#8236434)

It's happened before. Early shots from the Viking missions showed a blue sky. Or is that what you are referring to?

Key parts of Text (-1, Redundant)

kiwipeso (467618) | more than 10 years ago | (#8236399)

Even the color chips placed on the rover to calibrate the color photographs had shifted. What should be bright blue is instead bright pink; what should be bright green is brown.

The fundamental challenge in creating color photographs of Mars, he said, is that the cameras on the rovers take only black-and-white pictures, and the art of making color out of black and white never exactly reproduces what the eye sees.

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.

Apparently they have used the infrared instead of the red filter.

Article text (-1, Redundant)

SpinyManiac (542071) | more than 10 years ago | (#8236400)

How the Red Planet Came Down With the Pink Blues
By KENNETH CHANG

Published: February 10, 2004

ASADENA, Calif. -- It hardly seemed a surprise that the panoramic photograph of Gusev Crater, the landing site of NASA's Mars rover Spirit, showed a red landscape. After all, Mars is called the red planet because it looks red, a hue imparted by rust in the planet's ubiquitous dust.

But did NASA fiddle with the image to make it look that red? As Mars buffs have pointed out in recent weeks on Web sites like Slashdot.org, a closer look reveals that parts of the rover itself, in the foreground, are oddly garish. Even the color chips placed on the rover to calibrate the color photographs had shifted. What should be bright blue is instead bright pink; what should be bright green is brown.

A few days later, after the rover Spirit made its first roll onto the surface, it took a picture of the empty lander behind it. Again, the Mars buffs zoomed in on a detail. NASA's navy blue logo, often called the "meatball" because of its shape, was now the pinkish hue of rare hamburger. Perhaps more shocking, the spacecraft designers at NASA appeared to have a thing for hot pink: that was the color of the cables strewn around the top of the lander.

What was going on? On Jan. 31, during a lull in the control room at NASA's Jet Propulsion Laboratory, Jason Soderblom, a graduate student at Cornell who is a member of the science team, gave a talk explaining the odd Martian colors.

The fundamental challenge in creating color photographs of Mars, he said, is that the cameras on the rovers take only black-and-white pictures, and the art of making color out of black and white never exactly reproduces what the eye sees.

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. 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.

"This is actually true for a lot of blue pigments," Mr. Soderblom said. The infrared is so bright that it washes out the blue. "That turns this thing from a dark blue chip to a vibrant pink," he said. "This is an incredibly bright pink. The same thing is happening with our green color chip."

The infrared-for-red replacement is also "why the NASA meatball is red instead of blue," Mr. Soderblom said. The same is true of the cables. They are actually blue.

For the scientists, there are good reasons to focus on infrared colors rather than the visible red. "Iron dominates mineral color in the visible, and it causes everything to have shades of red," Mr. Soderblom said.

With the infrared filter, the different iron minerals emit different colors, and the camera can better differentiate between them. "We're trying to identify the minerals in the scene, and the way we're doing this is with subtle differences," Mr. Soderblom said.

What the eye sees, even when the colors are right, is not always quite what is happening. Mr. Soderblom showed pictures of the reddish "lily pads" around the landing site of the Spirit's twin, Opportunity, where its air bags bounced. The soil in the bounce marks is actually no more red than the darker surrounding soil, but for reasons not yet known, it emits less blue light. "By being not as bright in the blue, it appears more red to us," he said.

Still, there was no reason for the Spirit to see pink on Mars. When producing the panorama, the camera also used the red filter.

"We just made a mistake," said Dr. James F. Bell III, the lead scientist for the camera. "It's really just a mess-up."

21st C (0, Troll)

BenBenBen (249969) | more than 10 years ago | (#8236409)

So when are we going to have the technology to send _colour_ cameras to Mars?

I've seen them in some very expensive shops, so I'd have thought NASA would be able to shrink one down to the size of a football or so.

Re:21st C (-1, Flamebait)

BenBenBen (249969) | more than 10 years ago | (#8236506)

Yes, you got me, it's a troll.

Let me elaborate: The humour in my comment comes from the fact that, at heart, it contains a question; why did NASA not just send a colour camera, which as we all know are cheap and small? The comment used the notion of "irony" to point out that the giant might of NASA apparently didn't send a colour camera, but obviously this wasn't for technological reasons.

Jeez. Go look up the meaning of the word troll, doofus.

Re:21st C (-1)

Anonymous Coward | more than 10 years ago | (#8236571)

Well - I didn't mod you as a troll but I found your humour lacking considering that the cameras are color. Red, Blue and Green.

Re:21st C (1)

BenBenBen (249969) | more than 10 years ago | (#8236598)

RTFA. They're B&W with filters.

This means the 'film' is B&W. Now explain to me how they're colour?

Re:21st C (2, Informative)

RMH101 (636144) | more than 10 years ago | (#8236632)

they probably wanted better than 5MP resolution - you can get higher res with a high quality scientific b&w camera. if you take 3 still photos through RGB it's functionally identical to a colour camera - i.e. it IS a colour camera - and there would be nothing gained by sending up a "colour" camera that took a single shot and ended up with a poorer quality (but by your definition a real colour picture) result.

Re:21st C (0)

Anonymous Coward | more than 10 years ago | (#8236703)

There is no film. Just a bunch of sensors, like there is in a "colour" digital camera. It's just that instead of 3 types of sensor sensitive to different wavelengths, there is a single sensor type sensitive to all wavelengths and then multiple pictures are taken with different filters. That makes for a much higher resolution picture, a simpler camera and the possibility of taking pictures at wavelengths your "colour" camera couldn't.

Basically, a "colour" camera would be rubbish compared to this.

I hate Mars photos (2, Funny)

Rosco P. Coltrane (209368) | more than 10 years ago | (#8236415)

I tried showing them to my pet bull and he immediately became bad-tempered and generally unpleasant to be around of. He's much fonder of the Neptune shots from Voyager really...

Re:I hate Mars photos (1, Funny)

Anonymous Coward | more than 10 years ago | (#8236641)

Bulls are colorblind you moron; way to get an offtopic score.

Why don't they... (-1, Redundant)

CrackedButter (646746) | more than 10 years ago | (#8236420)

just use a 4 megapixel digital camera that anyone can buy from Compusa... why overcomplicate the issue?

Re:Why don't they... (1)

donnyspi (701349) | more than 10 years ago | (#8236458)

I think the ones in CompUSA are a tad sensitive to the extreme temps on Mars.....

Re:Why don't they... (0)

kiwipeso (467618) | more than 10 years ago | (#8236459)

Because a standard 4 megapixel camera would freeze on Mars.

Re:Why don't they... (5, Interesting)

Carl T (749426) | more than 10 years ago | (#8236526)

[...] just use a 4 megapixel digital camera that anyone can buy from Compusa

Quite possibly because it wouldn't survive the conditions on Mars. Or on the way there. Try deep-freezing your digital camera, then put it in a vacuum chamber, then in a really dusty sandbox, and finally subject it to a potentially lethal (for a human) dose of radiation, and see if it still works. Oh, and don't forget simulating the landing; heat it, vibrate it, and toss it on the ground.

Disclaimer: I wasn't there. I don't know exactly how the poor thing was treated. I'm not a member of the PETC (People for the Ethical Treatment of Cameras).

Re:Why don't they... (1)

snake_dad (311844) | more than 10 years ago | (#8236718)

Not to be nagging, but you forgot to mention the launch. The spacecraft suffers a lot of shaking and vibrating through launch. Not just the acceleration caused by the rocket, but also (and maybe even worse) the vibrations caused by the noise of the rocket engines. Part of the testing is actually done with huge loudspeakers

Re:Why don't they... (4, Interesting)

Lumpy (12016) | more than 10 years ago | (#8236569)

because that 4 megapixel camera from comp usa is a total piece of crap compared to the 1 megapixel B&W camera on the rover.

I have a old 2 megapixel digital camera that will beat the Best 4-6 megapixel consumer camera you can buy today. because of optics and the design of the CCD. (mine is a TRUE 2 megapixel whereas almost ALL camera's today sold as a 4 megapixel are really a 1.3 megapixel camera as you need 3 pixels for each photographed pixel.. (I.E. one for red,green and blue.)) plus the resolution of each color captured is vastly different, green usually being the best resolution while blue suffer's the most..

Nasa is not about to send the really low grade crap that is available to the cunsumer to another planet. they sent the real deal.

I suggest you actually learn about digital photography and why consumer grade "cameras" are utter junk.

Re:Why don't they... (1)

ctxspy (94924) | more than 10 years ago | (#8236608)

So tell me... where did you get a 'foveon' chip several years ago?

On top of that... 3 colors multiplied by 2 megapixels = the equivalent of 6 'consumer' megapixels.

Now... Current CMOS / CCD sensors on consumer cameras are up to 8 megapixels, with more professional cameras hitting 14 (Kodak for example).

And that's only in the D-SLR style. There's also Medium-format backs which have up to 20 something megapixels in resolution.

So... Please explain to me how your 2 megapixel sensor (which would btw invalidate all Foveon technology) surpasses these much higher res devices.

Thanks

Re:Why don't they... (2, Insightful)

v01d (122215) | more than 10 years ago | (#8236763)

On top of that... 3 colors multiplied by 2 megapixels = the equivalent of 6 'consumer' megapixels.

That was his point. The common 4 megapixel cameras are actually only 1.3 per color.

Regardless, megapixel count is hardly the most important aspect of a digital camera. The lens matters far more, as does the spacing and quality of the pixels. Really, NASA has a very interesting article on the topic.

Re:Why don't they... (1)

CrackedButter (646746) | more than 10 years ago | (#8236616)

I suggest you see the post for what it was meant for... a joke!

Re:Why don't they... (0)

Debillitatus (532722) | more than 10 years ago | (#8236857)

They're not utter junk, they're just consumer-grade, is all...

Well well well. (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8236864)

Aren't you just better than everybody.

Re:Why don't they... (0)

Anonymous Coward | more than 10 years ago | (#8236653)

Yeah, and then why didn't the fools just toss it in a tupperware container and duct tape the lot to a couple of cheap firework rockets and light the blue touch paper. I mean come on, how complicated can it be?

Re:Why don't they... (1)

CrackedButter (646746) | more than 10 years ago | (#8236783)

Exactly

Short version (4, Informative)

the_crowbar (149535) | more than 10 years ago | (#8236438)

On the panoramic picture: We goofed. It should not have been that red.

The other photographs are taken with the infa-red instead of visible red filter. Iron dominated the visible red spectrum. To allow a better analysis of the compounds found infa-red light is used instead.

<joke>No conspiracy here. Move on.</joke>

the_crowbar

Why don't they release the RGB too? (2, Interesting)

Tsar (536185) | more than 10 years ago | (#8236444)

They're taking images through blue, green, red and infrared filters. The color shift problem in the publicly released images is because they're blending in the infrared shot instead of the red shot, right? Why don't they just release the RGB images as well as the iRGB? They have all the images after all--why waste press conferences explaining the differences or lack thereof when they could just give us the pictures?

Re:Why don't they release the RGB too? (4, Informative)

Anonymous Coward | more than 10 years ago | (#8236491)

They release all the individual raw pictures on the mars rovers website. You are free to composite them yourself.

The engineers are focusing on the filters that return good science.

Re:Why don't they release the RGB too? (-1)

Anonymous Coward | more than 10 years ago | (#8236505)

Because they dont have the red shot duh.

Re:Why don't they release the RGB too? (4, Informative)

Seahawk (70898) | more than 10 years ago | (#8236510)

ALL data IS actually released.

Cant remember links from the top of my head(Search older /. stories), but several people have taken the raw data and composed their own versions of the colour photos.

AFAIR the things is a bit more complicated though - the cameras have 7 different filters, which have quite a bit of overlap, and doesnt peak at frequencies of light that directly could be used in an RGB image - so some fiddling is requered.

And TBH - I think its perfectly fine NASA doesn't focus on producing "correct" images if it doesn't mean better science! :)

Re:Why don't they release the RGB too? (4, Informative)

mlyle (148697) | more than 10 years ago | (#8236617)

My site [lyle.org] was one of the past ones featured on Slashdot.

Unfortunately, all data isn't released. There is not radiometric data or pointing data for pictures, spectrometer data, etc.

And NASA puts a hold on images they plan to use later for press conferences-- e.g. the individual PanCam pictures of the parachute and backshell weren't released. This goes directly against the promises they made pre-mission.

Re:Why don't they release the RGB too? (1)

Seahawk (70898) | more than 10 years ago | (#8236841)

Havent seen your site before - but VERY nice pictures! :)

I was just under the impression all imaging data was released...

Positioning data isnt really that important for creating truecolor images... ;)

Re:Why don't they release the RGB too? (2, Informative)

Fastolfe (1470) | more than 10 years ago | (#8236750)

They don't necessarily have images from all filters. In many pictures it's more valuable from a scientific point of view to use the infrared filter instead of the red filter. They may only command the rover to take those three pictures.

In most cases, the infrared filter is close enough to red that a composite still gives you a good image. They do occasionally take a picture with the red filter instead of the infrared, as the article states, but these aren't as useful for scientific purposes.

If the public's interest can be satisfied with a composite using the IR channel, and you get a lot more science done with it, doesn't it make sense to use it? Their mistake was in releasing color photographs without noting that the color might not be right.

Incidentally, all of the raw images are available on the NASA web site. Instructions for a do-it-yourself composite are available from the previous Slashdot article discussing the color of the images on Mars [slashdot.org] .

Gameboy Camera Color (3, Funny)

drfishy (634081) | more than 10 years ago | (#8236445)

Reminds me of the Gameboy Camera Color Project: http://www.ruleofthirds.com/gameboy/

Blue? Infrared? (2, Interesting)

Rufus88 (748752) | more than 10 years ago | (#8236481)


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."

If it's a *blue* pigment, why does it emit a *longer* (i.e. infrared) wavelength?

Re:Blue? Infrared? (0)

Anonymous Coward | more than 10 years ago | (#8236517)

If it's a *blue* pigment, why does it emit a *longer* (i.e. infrared) wavelength?

It ate too much tomacco, and the lung cancer inside of the pigment reflects infra-red radiation.

Re:Blue? Infrared? (2, Informative)

LordK2002 (672528) | more than 10 years ago | (#8236546)

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."

If it's a *blue* pigment, why does it emit a *longer* (i.e. infrared) wavelength?

Clarification of the original statement: "some materials, such as cobalt, which reflect light that appears blue to the human eye, also reflect light in the infra-red range".

It emits both blue and infra-red, neither has any effect on the other - we just only see the blue because the human eye does not detect infra-red.

K

Re:Blue? Infrared? (1)

CuriHP (741480) | more than 10 years ago | (#8236572)

It's blue because that is the only visible light it reflects/emits. That does not necessarily mean that it is the only wavelength reflected/emitted. It's just the only one your eye can see.

Re:Blue? Infrared? (3, Informative)

dwm (151474) | more than 10 years ago | (#8236581)

A material can emit light at various wavelengths, and at wavelengths quite different than that which it reflects, which is what you most commonly see in the visible range. It's quite possible for something to reflect blue light and emit light at wavelengths longer than the visible range.

Re:Blue? Infrared? (4, Informative)

Bill_Mische (253534) | more than 10 years ago | (#8236582)

I'd imagine because the blue colour corresponds to an electron transition in the d-orbital whereas the IR corresponds to a different transition or more likely to a change in mode of molecular vibration.

One of the few things I remember from my chemistry degree was that many pigments are far brighter in the UV region since the "normal" colour corresponds to a forbidden transition - i.e. one that involves a change of spin as well as change of orbital.

I do hope that wasn't a rhetorical question...

Re:Blue? Infrared? (0)

Anonymous Coward | more than 10 years ago | (#8236810)

Because it doesn't matter.

"Colour" of a pigment is defined only by what it reflects (it doesn't actually emit) across the visible spectrum, i.e. what the human eye can see. That's how pigments are chosen or designed.

RE: Why Don't They... (1)

CrackedButter (646746) | more than 10 years ago | (#8236579)

I'm scratching my head on this one, i said, or i thought i said something funny. It was funny at the time because I was watching the first episode of The Hitchhikers guide to the galaxy. My interpretation of its humour hasn't come over well then has it? What if i said the joke was harmless, no, mostly harmless, do i get modded +5 funny now?

before shooting comments off the hip about IR (2, Interesting)

WormholeFiend (674934) | more than 10 years ago | (#8236592)

maybe you should try taking infrared photos?

most of the digital cameras on the market dont have countermeasures to prevent IR exposures, so feel free to experiment with various infrared-transmitting, deep red and light red filters.

from my non-scientific experience, ultraviolet photos of rocks is more interesting than infrared.

Re:before shooting comments off the hip about IR (3, Interesting)

jandrese (485) | more than 10 years ago | (#8236705)

I don't know if my camera has a cheap filter or no filter at all, but it is more sensitive to infared than the naked eye. The easiest way to see this is to point a remote control at the camera, hold down a button and snap a picture. In the picture you can see the little bulb in the remote all lit up, even though it is invisble to the naked eye.

Re:before shooting comments off the hip about IR (1)

AndroidCat (229562) | more than 10 years ago | (#8236797)

Some camcorders now have filters to prevent IR exposures. Remember the fuss a few years ago when some people used the night-time settings on their camcorders to take "x-ray" shots which ignored clothing? (A few Slashdot articles about that.)

But what is this thing? (5, Interesting)

tjmcgee (749076) | more than 10 years ago | (#8236640)

The martian crab http://homepage.mac.com/thomasmcgee/ I know, I know, go ahead, mod me off topic. The truth is out there. Would anyone like to start a petition that requests NASA to try to get one more photo of this thing before they drive away?

Re:But what is this thing? (1)

tjmcgee (749076) | more than 10 years ago | (#8236670)

ugh, for the copy/paste challenged the Martian Crab [mac.com]

Re:But what is this thing? (1, Interesting)

Anonymous Coward | more than 10 years ago | (#8236732)

Much better images here: www.rense.com [rense.com]

I know Rense is a bit of a tin-foil hat site, but NASA have been strangely silent on this.

The original NASA picture is at: marsrovers.jpl.nasa.gov [large file] [nasa.gov]

Even the mainstream press are (deliberately?) ignoring it.

I don't think it's debris from the lander.

Re:But what is this thing? (2, Funny)

jgabby (158126) | more than 10 years ago | (#8236736)

I'm not certain, but this looks to me like it would have been in the path of where they drove the rover to the bedrock...might we have our first case of Martian Roadkill?

The REAL Story (2, Funny)

Anomalous Cowbird (539168) | more than 10 years ago | (#8236663)

Art Buchwald has the whole scoop here [washingtonpost.com] .

Sounds familiar ... (1)

Richard Allen (213475) | more than 10 years ago | (#8236675)

http://science.slashdot.org/article.pl?sid=04/01/0 9/1724246&mode=thread&tid=134&tid=152&tid=160&tid= 185

Seeing red (-1, Offtopic)

denisdekat (577738) | more than 10 years ago | (#8236824)

It must be the anger...
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