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We can get RAW versions for many ISS images, like those of airglow, e.g. ISS043-E-143486. But all the photos of the Milky Way taken from ISS that I found were posted on Twitter (e.g. this, Flickr or other social networks heavily tone-mapped, it's not possible to get the RAW sources, and apparently they are not in public domain as those obtainable from the NASA website.

But maybe I've missed something, or some other missions than ISS have colored RAW photos of the Milky Way. Or, if there are any colored colorimetrically calibrated images taken in the visible spectrum from space, this would also suit my needs.

I know there is Axel Mellinger's panorama, available as a FITS file from this page. But this one was made from Earth-based photos, so I'm not completely convinced of its hue correctness; besides, with the FITS data I failed to reproduce the hues from the JPEG preview like this one.

So, are there any non-tone-mapped or RAW images of the Milky Way taken from space available to the general public?

Ruslan
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  • The milky way has a fairly low surface brightness, so cones are not (fully) activated and it appears fairly colourless to unaided vision. So what are your needs? RAW doesn't mean "as appears to the naked eye". For example many emission nebulae would be quite brightly coloured, but have such low surface brightness that they just appear like misty smudges when viewed through a telescope. Any camera will do the equivalent of tone mapping, since the photosensitive material isn't the same as your retina. – James K Jul 09 '23 at 10:35
  • What does "RAW" stand for? No pictures are "raw" (if that's what you mean), they have all been processed in some respect by observing through filters and with cameras that have a non-uniform wavelength response. Do you just mean the unprocessed FITS files of the images? – ProfRob Jul 09 '23 at 11:19
  • @ProfRob RAW stands for any raw format such as CR2, NEF, DNG etc. The assumption is that, if the image was taken without additional filters, i.e. only the objective lens and the Bayer CFA, then the nonlinearity of the sensor data is much less than that of tone mapping and local adjustments applied after demosaicing and camera-to-sRGB transform. So far, with the cameras I used, this assumption was sufficiently good. – Ruslan Jul 09 '23 at 13:22
  • @JamesK Of course I'm not looking for "as humans see" representation. I'm interested in an image that would let me simulate taking a photo (with other objects in the scene too) with exposure and tone mapping of my own choosing. – Ruslan Jul 09 '23 at 13:24
  • @Ruslan the only difference between the RAW formats you're referring to and other non-RAW formats is that the so called RAW formats use lossless compression. Of couse the assumption is that the raw formats have gone through less human manipulation. But the aquisition of images from space cameras is a lot different than that of consumer cameras, so they generally don't use those formats. – Greg Miller Jul 09 '23 at 14:21
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    @GregMiller human (or even in-camera) post-processing is a huge distorter of saturations and relative brightnesses of different parts of the image. This is exactly what I want to avoid. As for the space cameras, many of ISS photos were taken on consumer cameras, e.g. ISS043-E-143486 was made by Nikon D4. In any case, if you know any source that would let me reconstruct sRGB colors reliably (from bands within the visible spectrum, with a well-specified color conversion matrix or filter response curves), this would answer the OP. – Ruslan Jul 09 '23 at 15:10
  • Would this do? https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=STS131&roll=E&frame=14516 – James K Jul 09 '23 at 18:34
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    Or this one, you can request the RAW file for this https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS044&roll=E&frame=45215 – James K Jul 09 '23 at 18:37
  • https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS006&roll=E&frame=28028 also has some milky way in the frame, and RAW is available – James K Jul 09 '23 at 18:40
  • @JamesK only the second link actually provided a real RAW file (the third one appeared to be the original JPEG by the request of raw). How did you search for these shots? – Ruslan Jul 09 '23 at 20:23
  • Searched for "milky way" including searching captions. I also searched for "galaxy" from the Nasa gateway to astronaut photography – James K Jul 09 '23 at 20:45

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Among astronaut photographs https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS044&roll=E&frame=45215 is a photo of airglow with the Milky Way in the background. A "RAW" image (actually NEF, Nikon's RAW file format) is available. This may be suitable for your requirements. Only a small part of the Milky Way is visible, and there is considerable motion blur on the whole image.

It was taken from space, but through the glass of the ISS viewing dome.

James K
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