!!!Mars Blue Sky & Water!!!

It is quite funny that most do not take notice of that fact. 5 years of taking pictures should amount to even more than 100 thousand.

But as you stated, its right there in front of everyone, right on NASA's site, clearly visible, verifiable, of the missing data sets.

Never Any Substantial Amount



Cheers!!!!

We dont need 100th decimal place filters to get a close representation of what the color is on Mars.

Viking had full RGB spectrum analog cameras and captured pretty darned accurate color images of Mars. But of course, NASA cranks up the RED channel on their published images. Basic layiering of those RGB raw image sets results in images that are not all RED.

This silly argument over true/not true color is just that..silly. Obviously those limited bandwidth filters on the MER rovers were deliberately made narrow to instigate this nonsense debate about true color, to give them and the doubters more to argue with, but they all forget one thing....the Viking raw data.

Careful combination of those data sets can reveal a 99 percent accuracy to what it looks like on Mars.

The MER images, because of the diliberate narrow designed filters, only gives an approximation.

Making full spectrum RGB filters would not have added any more weight, or any more significant cost of each filter. Each is a simple lens fitted into a wheel with holes for each filter lens that rotates in front of the camera apperature. They would not have taken up any more room on that wheel as the narrow filters.

If the approximation clearly shows Mars is NOT a red saturated planet, that is good enough to know that Mars is NOT a red saturated planet.

"Blue skies...nothing but blue skies....do I see" Humm hummm.



Cheers!!!!

reply to post by RFBurns

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Are you talking about images like these?




Yes, they look great, but we cannot be sure of the accuracy of the combination of the three images for each channel, as I said before in another thread, the problem is not the bandwidth, it's the way the photos are taken, taking three photos for each channel with automatic adjustments will not give the same results as taking a full visible spectrum colour photo, so some adjustments are needed, and those adjustments are the responsible for the reddish hue on Mars photos.

But maybe we can see in our lifetimes real colour photos from Mars, I have patience enough to wait.

PS: RFBurns, are you following me, you had not posted on this thread until I made my previous post.

PPS: I forgot to add that I like decimal places.

[edit on 26/3/2009 by ArMaP]

reply to post by ArMaP

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Wouldnt you say that even a 5 percent tolorance from center would be close enough to know that Mars is not entirely red?

I mean really....how much decimal place accuracy does there have to be to say "oh look, Mars does have a blue sky, its not always so red like NASA shows it to be, and even rocks and the dirt look more natural than in those red saturated images"?

I dont mind decimal places either but I dont need to nit pick it down to the millionth place to see the obvious either.

Trying to go so far past the point tends to make a person overlook the simplistic when simplistic is all that is needed.

Now even in your example photos above, neither one of them are red saturated.

Even the white on the probe looks white, not all reddish pink like that in NASA's images.

If you got those channels balanced out so that your white is white, regardless of light saturation, your going to get pretty darned close to the actual scene.

Its called "white balance"...and when you got proper white balance, that means you got all 3 channels of RGB properly balanced.

On a vectorscope, properly adjusted RGB channels will make the vectorscope dot hit dead center when looking at a white chart.

The chart on the Viking probe is just that, a white balance chart.

You adjust those channels for proper white balance, then your red, green, blue, grey, and black, will be correct.

Then everything else in the image will also be correct, or at the very least, within 1 percent.



Cheers!!!!

[edit on 26-3-2009 by RFBurns]

reply to post by RFBurns

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What happens when the white chart is being illuminated by a coloured light?

Doesn't it become coloured by that light? What would the vectorscope show in a case like that? The target chart is still white, but the image is not; correcting the image to make the white target look white will show the object (the white chart) as it is, but not as it can be seen on that scene, illuminated by a coloured light.

PS: I have never seen a vectorscope, so I cannot say what happens, but my knowledge in other areas makes me think that my interpretation of what would happen is probably correct.

I posted the following information in another thread, but I think it is relevant for this thread also, so I will repost it here.

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As promised, I made some tests to see if there is a difference between a normal photo taken with the visible spectrum and a photo made with three photos, one for each channel (red, green and blue).

My sister got me some samples of filters (they are not filters for cameras, they are light filters), and I chose the ones closest to the ones used by the Rover's cameras.

These are the characteristics of the three filters, showing what wavelenghts they let through them.

Red


Green


Blue


Combination of all three filters


It's noticeable that they are not narrow-band filters, so if the differences may be stronger with narrow-band filters I do not have any way of knowing it, at least for now.

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First, a colour target from a HP scanner.

Photo taken with sunlight and "auto levels" applied on Photoshop.


Same conditions, but composite made with three photos from each channel.


The colours on the composite look stronger, and they are farther from what I see than the visible light photo.

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Same colour target, under artificial light, giving it a more yellow tint.


Same conditions, but composite.


There is a bigger difference between these two photos than between those taken under sunlight, and that is probably because the blue filter, when using the artificial light, gave a very dark photo, so the auto levels did not had as many data to work as with the other channels, making a yellowish image.

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Now, a photo from a sunlit, outdoor view (what I see from my dinning-room window)


(click for full size)

And the composite for the same view, some seconds after.


(click for full size)

Some things that are visible on this comparison:
1. the clouds were too fast.
2. the blues are stronger, both the sky and a building on the background in the right side are bluer
3. all reds are weaker, the reflected light on the wall on the left side, for example, is not as red on the composite as it is on the "real" photo
4. the more neutral tones become a little weird, probably because of the lack of red, but I am not sure

One thing that is not visible (and that only I can see) is that the "real" photo is much closer to the true look of that scene, although it was a little darker than in "real.

Considering this, I think (even more than before) that just making composites with the Rover's photos creates images with too many blue and little red. That does not mean that the reddish NASA photos are correct (I have no way of knowing) but it makes me think that they are really closer to what can be seen on Mars.

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The camera was on automatic for all photos.
I used the camera's black and white (greyscale) feature for the three different channels' photos.
I used auto levels in the colour photos and on each channel to make it the most automatic possible, and closer to what we do with the Rovers' photos.