Jump to content
Join the Unexplained Mysteries community today! It's free and setting up an account only takes a moment.
- Sign In or Create Account -

Complaints about 'Fake' Colors in NASA Images


Claire.

Recommended Posts

Stop Complaining about 'Fake' Colors in NASA Images

We hear it all the time. Well, maybe you don't, but I get this thrown at me a lot. We see beautiful images released by NASA and other space agencies: ghostly nebulas giving tantalizing hints of their inner structures, leftover ruins of long-dead stellar systems, furious supernovae caught in the act of exploding and newborn stars peeking out from their dusty wombs.

Instead of just sitting back, relaxing and enjoying the light show the universe is putting on, some people feel compelled to object: But those colors are fake! You wouldn't see that nebula with your eyes! Binoculars and telescopes wouldn't reveal that supernova structure! Nothing in the universe is that shade of purple! And so on.

Read more: Science.com

  • Like 6
Link to comment
Share on other sites

 
  • 1 month later...

There is no such thing as 'true color' anyway.  It's a really dumb debate, and those who know their stuff, rightly, couldn't be bothered to explain it to the sort of folks who demand Da Truth.  The NASA guys know what the colors represent and how to resolve them back to real numbers if and when they need to.. and they just get on with their job.

 

It's a very complicated topic, and unless I see genuine interest (which NEVER comes from the NASA haters), I can't be bothered either.

  • Like 2
Link to comment
Share on other sites

2 hours ago, ChrLzs said:

There is no such thing as 'true color' anyway.  It's a really dumb debate, and those who know their stuff, rightly, couldn't be bothered to explain it to the sort of folks who demand Da Truth.  The NASA guys know what the colors represent and how to resolve them back to real numbers if and when they need to.. and they just get on with their job.

 

It's a very complicated topic, and unless I see genuine interest (which NEVER comes from the NASA haters), I can't be bothered either.

But I have often wondered, when people go to Mars what color will the sky be? If I cast my mind back forty years, when the first color images came in from Viking 1, the sky on Mars looked light blue. But then NASA realized the color charts on the lander didn't look right, and so adjusted the images and the sky became pink. Are we now sure what color the sky will be to the human eye - blue, pink, or what?

  • Like 1
Link to comment
Share on other sites

1 hour ago, Derek Willis said:

But I have often wondered, when people go to Mars what color will the sky be? If I cast my mind back forty years, when the first color images came in from Viking 1, the sky on Mars looked light blue. But then NASA realized the color charts on the lander didn't look right, and so adjusted the images and the sky became pink. Are we now sure what color the sky will be to the human eye - blue, pink, or what?

With all the auroras, rainbows, sunsets and sunrises, would you only call earth's sky blue?  I imagine Mars would be the same only of different hues. 

  • Like 1
Link to comment
Share on other sites

27 minutes ago, White Unicorn said:

With all the auroras, rainbows, sunsets and sunrises, would you only call earth's sky blue?  I imagine Mars would be the same only of different hues. 

Of course there are variations in the color of the sky here on Earth, for the reasons you mention. But generally speaking, because of Rayleigh scattering, the sky is considered to be light blue. 

  • Like 1
Link to comment
Share on other sites

There is a lengthy discussion about this somewhere, but I didn't keep the link.  No time now but I'll see if I can find it - in essence the conclusion (IIRC, is it is a bit like Earth in reverse.  Reddish hues in daylight but then some bluish tones at dusk dawn..?) - but suspended dust and the thin atmosphere meant much more variability. (although we have more clouds of course)..

Because our eyes adapt their white balance in accordance with earth conditions, your actual mileage/colour perception may still vary dramatically, when you do get to go to Mars....

  • Like 1
Link to comment
Share on other sites

Hmm.  Haven't found the link yet, but here's a much older discussion about Viking & Pathfinder images, and I'd recommend you read the text which talks about just some of the reasons why 'true' color is virtually impossible.

http://www.donaldedavis.com/PARTS/MARSCLRS.html

ALL color images are recorded on sensors or film and then viewed through a human eye.  When the light is recorded by the pixels in the digital camera (or the film grains), it is either passed through color filters, or recorded by individual Red/Green/Blue pixels, in order to create a color image.  At some point, judgements have to be made and the final colors that appear depend on those judgements and processing - 'raw' images straight from the camera do NOT inherently have any 'true' accuracy built in.  That's because the color filters/RGB sensors do NOT match the sensitivity curves of the human eye, plus the differences vary non-linearly over the entire dynamic range, from bright to low light.  And not only does the human eye also have non-linearities (but different ones!), it also has built in color adaption (white balance) so it will tend to 'fix' the colors.  Even that isn't 'simple' - it is not just embedded in the eye's rods/cones - it is also dependent on the brain/eye interface, and also different chemicals that the eye uses to adjust for too much or too little light.

PLUS, as if it needed to be worse!, the surrounding scene, the thin atmosphere and the dust content, as well as the angle of the Sun and just exactly where you are looking, will also cause perceptual changes...

 

In summary, the best guesses for what a human eye would see are:

- typical sky, midday - light yellow-brown, like 'butterscotch'.  More dust in sky = increased red/pink tones.

- typical sky near sunset/rise - pinkish red, but more blue-white close to the Sun.  Note that dusk/dawn lasts much longer on Mars due to scattered light from the dust in the atmosphere

- in regions with a high water/ice content (in very thin cloud/layers, may not be visible as clouds), sky may tend towards purplish-violet hues.

 

That's from many sources including the Wiki..

But I'll keep looking for that better coverage..

Edited by ChrLzs
  • Like 2
Link to comment
Share on other sites

9 hours ago, ChrLzs said:

summary, the best guesses for what a human eye would see are:

- typical sky, midday - light yellow-brown, like 'butterscotch'.  More dust in sky = increased red/pink tones.

- typical sky near sunset/rise - pinkish red, but more blue-white close to the Sun.  Note that dusk/dawn lasts much longer on Mars due to scattered light from the dust in the atmosphere

- in regions with a high water/ice content (in very thin cloud/layers, may not be visible as clouds), sky may tend towards purplish-violet hues.

 

I found this article, which you may have read at some point. It seems, and it is understandable, that it was necessary haste that led to the "blue sky" image being released to the public.

http://history.nasa.gov/SP-4212/ch11-4.html

I am surprised there is no conspiracy theory based on this, along the lines of: "NASA knows that Mars is very much like the Earth, but the images they release make it look like a very alien place, and this is to hide the fact that there are cities up there."

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.