When we see deep space nebula pictures, is that how we would see them with the naked eye?

Question

Or are we seeing them through filters.....

Pictures such as this one...

http://www.omniscopic.com/blog/uploaded_images/OrionNebula-774263.jpg

Answer 1

If there is any natural color in those nebulas, the light is too faint to stimulate the cone cells of your retina. Even with a giant telescope and low magnification, the light is just too dim for you to see it live in color. To get those picture, it is necessary to collect the light for several minutes or even hours. This can be done the old fashioned way with photographic film or the new way with CCD digital cameras.

Answer 2

Those are all "false" color images. So, no, they are not as the naked eye would see them.

HTH

Charles

Answer 3

This happens to be the real colours, not enhanced ones.

Unfortunately, our eyes are very poor cameras.  They do not react equally to all colours (we perceive green far more easily than any other colour) and they do not react linearly to changing brightness.

A CCD camera has one big advantage:  if star A is twice as bright as star B, its image will have twice as many electrons (trapped in the pixels) as B's image.

Ten times as bright, ten times the number of electrons.

The CCD camera can do this over a range of tens of thousands (a computer screen around 256 levels and our eyes around 8 levels or so).

That is the reason why the colours on such pictures appear enhanced and "not true".  But they are true.

However, there are also plenty of astro images where the colours were enhanced.  That is because lots of images are taken with special cameras that detect wavelengths we cannot see (e.g., infrared, ultraviolet, X-ray...).

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In general, astro images are always taken through filters.  In order to get a true color image, we will take images with a red filter, a green filter and a blue filter (more than one image with each).  We often identify a star whose true colour is known (for having been studied a lot) and we tell the computer to balance the colours so that this particular star comes out exactly right (if we are lucky, there will be more than one such star in the field).

What we get must then be the true colours.

Unfortunately, when we observe directly by eye, the light levels are not bright enough or close enough in intensity for our eyes to detect the real colours.  Faint nebulae are often reported as greenish or even without colour by visual observers.

Answer 4

obviously not, since they don't look like that to our eyes.

many pictures are shot in natural colour, they are what we would see if our eyes were 10000000 times more sensitive to light.

Answer 5

good question.

no. you would see it differently.

i'm not quite sure as to how that all works though.. :)

Answer 6

No.  The colors are enhanced.  If you saw them with the naked eye the colors would be very faint, or it would just look gray.

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Answer 7

the pics such as the one you're examining are timed exposures ........ and they're long exposures to collect enough light to capture the various colors.

strictly speaking, they're not "color enhanced" they're just very long exposures.

the most you can see with the naked eye is a vague haze. a 14-inch scope can begin to bring out the faintest green colors sometimes.

Answer 8

Charles and 'aladdin' are very correct. The colors in the photos are enhanced- for admiration. With the naked eye, they would seem much more faded.

Answer 9

Unfortunately no. Through a telescope or even binoculars nebulae appear as nothing more than varying shades of grey.

The beautiful images are the result of using special filters on the telescopes that bring out the color signature of the various elements.