Why false colour or near true colour?

[Pyromaniac605]

I wasn't sure where to put this, I hope it fits here okay.

Anyway, I was wondering why almost all probes/satellites/rovers etc. that we send to other planets have take false colour or near true colour pictures.
Is it really that hard to put a simple normal (Albeit beefed up) colour camera on them? Why do they almost always use false or near true colour?

 

[agentgonzo]

The probes that we send into space are there to do specific studies - not take pretty pictures for our gratification (although this is a very happy side-effect). As such, the cameras that they put on the craft are tuned to the frequencies (colours) that they want to observe and generally do not match what our human eyes can see. They could stick a colour camera on it, but it would provide little-to-no additional science and from the mission point-of-view take up room that something else could have, be an unnecessary drain on power and data transfer and be something else that could potentially go wrong.

Sometimes they can have more than three different colour detectors giving them more than three degrees of colour information. The false colour images are normally generated with the scientific study in mind so the colours will be used to highlight important things for the scientists. If they also look pretty, they will release them to the media to make us all go gooey and warm inside.

 

[tblaxland]

No "simple, normal" camera takes "true colour" photos anyway - at least they are not true in the sense that they don't match your perception of the scene. This is partly due to the limited dynamic range of both the camera sensing element and whatever display device you are using (monitor, photo paper, etc). It is also due to your perception being altered by your brain simplifying and extracting patterns from the scene. The very thing that makes your brain good at pattern recognition (such as seeing danger coming your way) makes it very difficult for you to see "truly". You are an illusionist's playground

 

[N_Molson]

Yeah and anyway, I'd bet that the way we perceive colors varies from an individual to others.

I have a friend that has some difficulty to make the difference between close colors. Still, he loves photography and is skilled at it. His domain of speciality is, of course, grayscale pictures.

So it's hard to say where is the "truth" in terms of colors. RGB values give a good approximation, but (255, 0, 0) is a pure abstraction, not a perception of a "pure" red color.

That always seemed a complex matter to me. Probably all the "recolored pictures" are also a matter of artistic impression. :hmm:

Now it could be interesting to wire our eyes to a computer and get the output signal in RGB values... And to compare results to see how much difference there is in the same situation. Well, someone surely tried that somewhere... :shifty:

 

[agentgonzo]

Yeah and anyway, I'd bet that the way we perceive colors varies from an individual to others.

Some people don't have all three colour sensors and are colour blind. Some people are know to have 4 different sensors (another one further into the ultra-violet) and can differentiate colours us 3-dimensionally-coloured individuals can't.

 

[boogabooga]

The probes that we send into space are there to do specific studies - not take pretty pictures for our gratification (although this is a very happy side-effect). As such, the cameras that they put on the craft are tuned to the frequencies (colours) that they want to observe and generally do not match what our human eyes can see. They could stick a colour camera on it, but it would provide little-to-no additional science and from the mission point-of-view take up room that something else could have, be an unnecessary drain on power and data transfer and be something else that could potentially go wrong.

Sometimes they can have more than three different colour detectors giving them more than three degrees of colour information. The false colour images are normally generated with the scientific study in mind so the colours will be used to highlight important things for the scientists. If they also look pretty, they will release them to the media to make us all go gooey and warm inside.

LOL. :lol:

When I went to see the Hubble IMAX movie with some friends a few weeks ago, I mentioned in the car ride home how those were false color images that were probably intentionally colored to "look good." One of my friends LOVED the Hubble movie and we nearly got into a fight over it. Guess that's what I get for being a know-it-all jerk.


More to agentgonzo's point- the so-called visible spectrum is a only a very small segment of the overall EM radiation band that extends from radio/microwaves all the way to gamma rays. What you see is a band that just so happens to be associated with the fairly low energy absorptions that take place in many important, large organic biomolecules. So, seeing in the visible spectrum is really great if you want to spot ripe fruit on a tree. If you want a trace gas analysis of an atmosphere from orbit (and so on), then not so much.

BTW, on the false color topic, has anyone tried the exotic celestial background pack from the Orbiter site?