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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?

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  • $\begingroup$ 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. $\endgroup$
    – James K
    Jul 9, 2023 at 10:35
  • $\begingroup$ 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? $\endgroup$
    – ProfRob
    Jul 9, 2023 at 11:19
  • $\begingroup$ @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. $\endgroup$
    – Ruslan
    Jul 9, 2023 at 13:22
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    $\begingroup$ @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. $\endgroup$
    – Ruslan
    Jul 9, 2023 at 15:10
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    $\begingroup$ Or this one, you can request the RAW file for this eol.jsc.nasa.gov/SearchPhotos/… $\endgroup$
    – James K
    Jul 9, 2023 at 18:37

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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.

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