I cannot seem to find the best search parameters on this site to pull up old posts on this subject as something tells me it has been discussed before.

Is it true that any of the more colorful photographs of the universe are photoshopped or somehow digitally enhanced? If so, what do these colorful images look like without the touchup?

Are you using 'advanced search' facility?

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clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.

Sorry ...budda, my searched-results link was all-over-the-place..

There are a host of extremely experienced astrophotographers here, who would gladly answer your question(s).

I don't think Hubble captures would be photoshopped, in the regular sense/usage of the term....

No other instrument on our planet can shoot like, what we can, through Hubble.

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clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.

Here is an interesting link on how the Eagle Nebula photo from Hubble came to be.

http://www.pbs.org/wgbh/nova/science...owi-flash.html

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Defining science can be difficult. It’s a method, a way of looking at things. It’s a compendium of facts, knowledge, data. It’s a tool, used to investigate the world and to make sure we don’t let our biases, egos, and wishes get in the way of finding what’s real. Science (and skepticism) boil off the dross and leave the pure nugget of reality. ~Phil Plait

No problem. Yeah i tried the exact same search you did and it turned up too many results that lead nowhere.

I was still hoping for some of the people who have actually done the "photoshopping" to give their 2cents. :-)

This thread from the Conspiracy Theory (CT) forum talks about the processing of digital photos.

In my mind, there is a big difference among saying an image was "photoshopped", "digitally enhanced", and digitally processed. To me, saying it was "photoshopped" implies that a photo was changed with some idea of deception or changing the contents.

Keep in mind, Hubble, and most modern space probes, do not produce "photos" in any conventional sense of the word. They produce digital data, sometimes in ranges beyond the preception of the human eye. This data has to be processed in some form for us to see. You can't have a "photograph" of UV or x-ray data, for example.

Are you implying some sort of deceit or coverup by NASA Zenbudda?

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

Producing a color composite image from multiple filters requires a number of choices to make it interpretable to the viewing eye. What range of brightness in each filter do you map to the black-white dynamic range? Do you do that linearly, logarithmically, with a hyperbolic sine function. or a customized function? How do you balance the brightnesses of the various filters to give a usable color balance while retaining as much of the image information as possible? Do you use some masking algorithm to avoid saturating bright areas when showing faint ones?

These are all choices with multiple defensible answers. If that qualifies as photoshopping, we're all guilty. (On the other hand, since [O III] is visually green and H-alpha is red, I would argue that the "Hubble palette" for nebulae is wrong; there exists an equally easy and more visually correct choice for mapping the usual [O III]-H-alpha-[S II] filters to RGB colors, which gets 2 of the 3 right and makes the third only partial).

Thank you Swift, again. I was thinking along those lines too last night, when first reading OP.

But you guys answer / discuss / explain it better.

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clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.

__________________
At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

zenbudda, if you search for the work of... erm... blanking... the Mexican guy, you'll get an idea of how Hubble's colourful vistas come into being. They are composites of exposures capturing single wavelengths. Since colour in the sense of digital images is a composite of red, green and blue, assigning an intensity of one of these colours to an intensity of a wavelength captured in the exposure and then putting it all together, you get the technicolour dream land you see.

you mean, Cesar Cantu...Glom...
sorry, can't use charmap on this sillymoo browser, for correct spelling...

Well, there are many astrophotographers here...masters all...
Do go, and have a look at their exquisite posts/compositions and explanations.

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clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.

No. It's mexhunter.

While I enjoy a good conspiracy theory read, no, that is not what I am suggesting. I guess the internet "meme" behind the word "shopped" does imply a sense of misguiding the viewer. This is not what I meant. I was being literal with my question. Does astro-photagraphy use some sort of photo manipulation software? I guess what I'm interested in knowing is "how much" is added/taken away?

NickW posted how they composed the Eagle nebula photograph. Keeping that technique in mind, how close and under what type of conditions (atmospheric, shaded, etc) would you have to be in order to see these celestial objects this way?

This sounds like "an" answer I was seeking. Thanks for this input. Is there anyway to convert said photo myself into a more "true" color? I don't quite understand the lingo you're using regarding the colors.

I found a bunch of stuff about processing images from the Mars rovers, particularly the PanCam. Here is a NASA document called the "MER/Pancam Data Processing User's Guide". This fellow's website has a lot of information too.

And here, from hubblesite.org is a series of webpages entitled "The Meaning of Color", an excellent explanation of their process (thought not technically detailed).

__________________
At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

Same... whatchamacallit....difference...er Geek Glom

__________________
clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.

Because i have just finished the 'Elephant Trunk Nebula' i just wanted to answer the questions about the Photoshoping of astroimages. The Hubble technique is way more difficult then normal color imaging. It need hours and hours of patient, processing (with the normal sence of the word), try-out and delete, reading and learning the rite way from expert of astroimaging, etc. It is not only putting the filters and start capturing, u must know exactly what u are doing.

And for the people that think that Photoshop is the main tool for capturing the heavens i wanted to say that this is very very wrong. Photoshop and other softwares are just the end-processing tools that help a little to show some details that the eye can not see so easily. What count is work, work, work outside under the night sky. If the person that try to capture the wonders of the Universe dont love what he is doing, then its over. Better dont do it at all.

Thanks
Antony

The raw images are almost always archived forever - or however long interest remains in them, in light of money, space, time budgets. Probably a very long time, given modern cheapness of digital storage.

Every image produced from the raw images takes something away from the originals. But hopefully they add something too in that some part of the data can be better understood. How much is taken away or added depends on the process used. It varies.

But the original is always there for someone else to process. So, one way to look at it is: nothing is taken away or added.

I'm reminded of a very recent article about an Ansel Adams (Wikipedia) exhibit. It's not about his final honed skills, but about his growth to get there, tracking especially images made early in his career. Sometimes, over long spans, he reinterpreted his own work, using original negatives and printing them differently years later, perhaps with better technique, with better tools, too. The contrasts (heh) are compelling.

Were someone lucky enough to have access, they could also (re)interpret those original negatives, and get still different results -- maybe better, but probably not better than Ansel the Great. But different.

PS: the Bad Astronomer took a walk through image processing a long while ago, in article What Color is Mars?.

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Hi zenbudda:
That normally are not show these raw photos.
It is half of the process, before which you will see.
You compile frames, you calibrate them and you register, make a subtractions flaps, darks and bias, for each channel of the RGB.
As I have terrible English, I will do showing it the photos.
In this case, it can seem but complicated, because the filters are not red, green and blue.
They are of narrow band, less than 540nm is the light band that leaks.
They are for emissions of hydrogen-alpha, oxygen and nitrogen.
Soon they are combined with a software and you assign, in this case, nitrogen for the red one, the hydrogen for green and oxygen for the blue one.

Hydrogen-alfa:



Oxygen:



Nitrogen:



Later you process, to diminish the thermal noise of the chip of the camera, to compensate light polution and the basic noise of the deep space. And you obtain a result similar to this:



The resolution of the photos is low, because each post be a limit.
Many greetings
Cesar

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