Deep space photography and false colour

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Kloofvreter

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I don't quite get this. Can someone explain false colour to me simply? :o

It's clear that these awesome multicoloured photos of galaxies and deep space in general, is not actually a true reflection of how it actually looks. So what is this false colour, and why would it NOT be possible just to snap a picture? Or has it something to do with not actually seeing anything, but rather detecting?
 
Because they are at wavelengths invisible to the human eye. The same way thermal images are portrayed from blue to red to indicate temperature.
 
abzo said:
Because they are at wavelengths invisible to the human eye. The same way thermal images are portrayed from blue to red to indicate temperature.
Click to expand...

Yeah I had an idea that it had something to do with infrared and ultra violet, etc etc. So basically to the human eye, space would just be blackness? :o
 
False color refers to a group of color rendering methods used to display images in color which were recorded in the visual or non-visual parts of the electromagnetic spectrum. A false-color image is an image that depicts an object in colors that differ from those a photograph (a "true-color" image) would show.

In addition variants of false color such as pseudo color, density slicing and choropleths are used for information visualization of either data gathered by a single grayscale channel or data not depicting parts of the electromagnetic spectrum (e.g. elevation in relief maps or tissue types in magnetic resonance imaging).

https://en.wikipedia.org/wiki/False_color
 
MKFrost said:
False color refers to a group of color rendering methods used to display images in color which were recorded in the visual or non-visual parts of the electromagnetic spectrum. A false-color image is an image that depicts an object in colors that differ from those a photograph (a "true-color" image) would show.

In addition variants of false color such as pseudo color, density slicing and choropleths are used for information visualization of either data gathered by a single grayscale channel or data not depicting parts of the electromagnetic spectrum (e.g. elevation in relief maps or tissue types in magnetic resonance imaging).

https://en.wikipedia.org/wiki/False_color
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I have read this, just wanting someone to simplify it. :o
 
Slootvreter said:
Yeah I had an idea that it had something to do with infrared and ultra violet, etc etc. So basically to the human eye, space would just be blackness? :o
Click to expand...

not necessarily, you'll see whatever is in the visible spectrum, for example mars IS reddish orange, that's not false colour.

In astronomy, the areas of interest (for example molecular gasses) are usually in the invisible spectrums which is why false colour is then used.
 
Slootvreter said:
Yeah I had an idea that it had something to do with infrared and ultra violet, etc etc. So basically to the human eye, space would just be blackness? :o
Click to expand...

No. Some deep space photographs are made by combining images from different wavelengths of light but not all of them. Here is a page which tells you how the put those beautiful Hubble images together: http://www.spacetelescope.org/extras/tutorial/
 
Slootvreter said:
It's clear that these awesome multicoloured photos of galaxies and deep space in general, is not actually a true reflection of how it actually looks. So what is this false colour, and why would it NOT be possible just to snap a picture? Or has it something to do with not actually seeing anything, but rather detecting?
Click to expand...

Based on my simple understanding:

The multicoloured photos of galaxies are true reflections using wavelengths of light that are imperceptible to the human eye, and represented in a colour most accurate to what the eye can identify with, in relation to the colour that it actually is.

So no, it is not impossible to take such a picture, it is just impossible for us to interpret it in the exact same way given our limitations of colour perception.
 
Maverick Jester said:
Based on my simple understanding:

The multicoloured photos of galaxies are true reflections using wavelengths of light that are imperceptible to the human eye, and represented in a colour most accurate to what the eye can identify with, in relation to the colour that it actually is.

So no, it is not impossible to take such a picture, it is just impossible for us to interpret it in the exact same way given our limitations of colour perception.
Click to expand...

So this is not actually how, for example, the Carina Nebula would really look?

stellar-nursery-carina-nebula-chaotic-activity-three-light-year-tall-pillar-of-gas-dust-nasa-jpl.jpg
 
Slootvreter said:
So this is not actually how, for example, the Carina Nebula would really look?

View attachment 57501
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It is, but it isn't... if that makes sense.

Using an arbitrary example- you would see a door as the solid unit, not as the individual splinters that form the piece of wood making up the door, correct? Similar situation here, where the additional wavelengths of light displayed in the Carina Nebula picture exist, you just do not have the ability to interpret them.
 
Maverick Jester said:
It is, but it isn't... if that makes sense.

Using an arbitrary example- you would see a door as the solid unit, not as the individual splinters that form the piece of wood making up the door, correct? Similar situation here, where the additional wavelengths of light displayed in the Carina Nebula picture exist, you just do not have the ability to interpret them.
Click to expand...

I am getting a bit of this, but this kind of thing has only recently tickled my interest. So basically this is a raw image of a nebula, as it would look to the naked eye? Or not exactly.

raw2.jpg
 
Slootvreter said:
I am getting a bit of this, but this kind of thing has only recently tickled my interest. So basically this is a raw image of a nebula, as it would look to the naked eye? Or not exactly.

View attachment 57505
Click to expand...

Probably, yes. And it not only looks boring, but must be rather useless to scientists when using it to better understand the chemical composition of nebulae...
 
I found the images on this page quite helpful ... not the most technical explanation but it really helped me to visualize how these space scopes see things and how these composite images are created.

It's a real pity the human eye only "sees" a tiny fraction of the light spectrum :(
 
Deezil said:
I found the images on this page quite helpful ... not the most technical explanation but it really helped me to visualize how these space scopes see things and how these composite images are created.

It's a real pity the human eye only "sees" a tiny fraction of the light spectrum :(
Click to expand...

That is a great link. So basically this is how it would look through our eyes?

Hubble_visible.jpg
 
Can't wait to see this one:

[video=youtube_share;QNce_8WHTGc]http://youtu.be/QNce_8WHTGc[/video]
 
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