Skip navigation
Van-Paul
Currently Being Moderated

The availability of color space in RAW, TIFF and JPEG files

Jan 5, 2013 5:09 AM

This is useful if your new to DSLR photography.

This is Nikon response on my question in the discussion: View photo metadata

I'm assuming that you know that Adobe RGB shows about 50% and sRGB 35% of CIELAB color space.

 

  1. In a DSLR camera like the Nikon D800 you can select a color space (Adobe RGB or sRGB) in the shooting menu.
  2. In Adobe Lightroom 4.3 the RAW metadata shows no color space info. Therefore I asked why not?
  3. In the (Dutch) Nikon D800 manual on page 84 (about RAW) and 274 (about color space) and Nikon FAQ website there is no descripton about the color space availability/behavior in RAW, JPEG and TIFF files.
  4. In the book "Mastering the Nikon D800 by Darrel Young" on page 125 - 126 is written: "If you shoot in RAW format a lot, you may want to consider using Adobe RGB....."
  5. All experts on this forum answered: color space does not apply/affect the RAW data file or RAW files have no color space.
  6. The respone of Nikon Europe Support (Robert Vermeulen) was: In Nikon D800 NEF RAW files both color spaces (Adobe RGB and sRGB) are always physically available. In JPEG and TIFF files only the in the shooting menu selected color space is physically available. So the forum experts gave the correct answer!
  7. Of course you can convert afterwards a JPEG or TIFF file with sRGB color space to Adobe RGB but you don't get more colors.
  8. When you install the Microsoft Camera Codec Pack or FastPictureViewer Codec Pack they only show color space metadata for JPEG and TIFF files and nothing for RAW because color space "doesn't exist". I thought the codec packs removed the color space metadata for my RAW files.
  9. Adobe Lightroom also can not show color space for RAW files because that "doesn't exist".
 
Replies
  • Currently Being Moderated
    Jan 5, 2013 5:24 AM   in reply to Van-Paul

    Van-Paul wrote:

     

    1. The respone of Nikon Europe Support (Robert Vermeulen) was: In Nikon D800 NEF RAW files both color spaces (Adobe RGB and sRGB) are physically available. In JPEG and TIFF files only the in the shooting menu selected color space is physically available.

    I still think this is an evasive answer that doesn't really pinpoint the exact chain of events that take place. They are:

     

    1. The raw file contains the naked data captured by the sensor. This is just a very dark grayscale image.

     

    2. In the raw converter it is encoded into a working color space to process the information. In Lightroom this is known as "Melissa RGB", or linear gamma Prophoto. It is also demosaiced to bring back the color information.

     

    3. From Lightroom it can be exported to one of the familiar color spaces like sRGB or Adobe RGB. This is, in principle at least, a normal profile conversion.

     

    These three steps are what the camera does to produce a jpeg. So the basic steps are the same, the camera is just doing it automatically (and usually butchering the image in the process...).

     

    This Darrell Young is, I'm sure, an excellent photographer, but in this he is seriously confused and just propagating a common myth. Anyway, thanks for bringing up this discussion, hope you didn't object too much to the tone of the answers... Our only concern here was to get this right and with no room for misunderstanding.

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 5, 2013 7:15 PM   in reply to Van-Paul

    Dunno if Nikon's response cleared anything up for you or not, but let me re-iterate a few things:

     

    Raw files include:

    * raw-data

    * jpegs

     

    The color space very much influences the jpegs in the raw file.

    The color space has zero effect on the raw-data, or it's rendering in Lightroom.

     

    Thanks for keeping us in the loop.

     

    Cheers,

    Rob

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 6, 2013 1:34 AM   in reply to Rob Cole

    Yes, there is actually a small jpeg in there too...didn't think of that (a fifth column...)

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 6, 2013 1:42 AM   in reply to twenty_one

    twenty_one wrote:

     

    Yes, there is actually a small jpeg in there too...didn't think of that (a fifth column...)

    Actually, there are two jpegs in a raw NEF file: a small one which can be used as thumbnail, and a big one - full-rez.

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 7, 2013 5:07 AM   in reply to Van-Paul

    As others say, a raw file has no colour space, as it isn't data in any standard colour model.  Obviously it does have colour information: pixel data represents the spectral response of the micro filters in the camera sensor. 

     

    Lightroom Develop Module converts the data to ProPhoto RGB with linear gamma, using the Adobe profiles, which contain information about the spectral response of each supported camera's sensor. 

     

    By the way, ProPhoto with linear gamma isn't "Melissa RGB", which is ProPhoto RGB with an sRGB gamma, and is used for Develop Module histograms only. 

     

    Library Module uses Adobe RGB (which is the colour space used by the Lightroom previews, which are stored as 8-bit jpegs). 

     

    As Rob says, the colour space setting on the camera affects the colour space used by the embedded jpeg(s). 

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 1:31 PM   in reply to CSS Simon

    CSS Simon wrote:

     

    Library Module uses Adobe RGB (which is the colour space used by the Lightroom previews, which are stored as 8-bit jpegs).

    FWIW: Although previews are usually AdobeRGB, sometimes they are sRGB (not sure why).

     

    This is usually only pertinent when recovering previews from the deep recesses of the preview subsystem, still...

     

    Rob

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 1:43 PM   in reply to Rob Cole

    Rob Cole wrote:

     

    FWIW: Although previews are usually AdobeRGB, sometimes they are sRGB (not sure why).

     

    This is usually only pertinent when recovering previews from the deep recesses of the preview subsystem, still...

     

    Rob

    Curious!  I didn't know that.

     

    I wonder why?  It might make sense if the original image is tif or jpeg (as opposed to raw) and in sRGB - or have you seen it on previews for raw images?

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 2:01 PM   in reply to CSS Simon

    I never checked. I just noticed it when writing PreviewExporter. It could very well be that jpegs etc. that are in sRGB in the first place are the cases for sRGB previews - I just don't know. You may be able to answer that question by spending a moment issuing SQL queries...

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 2:11 PM   in reply to Rob Cole

    This is interesting, I do not normally import files other than raw into my Lightroom catalog, so I have no experence as to what takes place. I  understand and see the operation when the previews are being created for the raw files.

     

    Are previews also created when JPEG and TIFF files are imported? If so why is it necessary?

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 2:13 PM   in reply to Van-Paul

    Van-Paul wrote:

     

    I asked Nikon and you're right...

    Thank goodness! Had Nikon said we were wrong we would have never convinced you! .

     

    Beware: the reps who answer questions are sometimes less qualified, technically, than the users on this forum. Granted, they are usually more qualified at weasle-wording, ambiguity, obfuscation, regurgitation, ..., if they really don't understand what's going on .

     

    Rob

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 2:45 PM   in reply to DdeGannes

    ACR cache entries are for raws only, but lib-previews are for all file types.

     

    The purpose is (primarily) for quick(er) display in library module. - jpegs and tiffs can also have a bunch of adjustments, and it takes some time to bake a view. Dunno if rgb previews are created upon import or deferred until adjustments are made - I suspect the former, but I suppose the latter could be a possibility, although I doubt it:

     

    There are (up-to/usually) 7 different preview images created for each file, from full-rez to tiny - each are half the dimensions  of the next bigger - thus the term "preview pyramid".

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 2:59 PM   in reply to Rob Cole

    Thanks for the info. Just following the thread.

     
    |
    Mark as:
  • Andrew Rodney
    1,388 posts
    Apr 16, 2009
    Currently Being Moderated
    Jan 8, 2013 2:59 PM   in reply to Van-Paul

    Van-Paul wrote:

    1. In a DSLR camera like the Nikon D800 you can select a color space (Adobe RGB or sRGB) in the shooting menu.
    2. In Adobe Lightroom 4.3 the RAW metadata shows no color space info. Therefore I asked why not?

    Raw files don't have a known color space. There is a assumed color space a raw converter has to make but for us end users, just considering this a non rendered, non demosaiced 'Grayscale' file. This is why you don't see any info about a color space in Adobe raw converters, however you can render and export actual RGB data in any number of color spaces. If you capture a JPEG, the setting on the camera affects this conversion from raw to JPEG in-camera. It has zero effect on the raw data itself. The setting will affect the camera histogram but that is divorced from the raw and the subsequent processing. So you can pretty much forget about the Histogram telling you much about the potential rendering and color space of the raw data.

     

    Adobe raw processors use a varient of ProPhoto RGB for processing. That does not mean the products assume the raw data is in that space (it isn't) and they have to come up with some assumption about the color space before they get to this step. About the only people who might know the color space would be the manufacturer of the camera system or perhaps someone who can gain the spectral sensitivities of the chip. But in the end, it doesn't really matter. The data the camera captures isn't a colorimetric space so it's not useful to even think about that data in terms of 'color space'. The idea it's un-rendered Grayscale is probably the best one for we end users.

     
    |
    Mark as:
  • Currently Being Moderated
    Jan 8, 2013 3:48 PM   in reply to DdeGannes

    DdeGannes wrote:

     

    Thanks for the info. Just following the thread.

    Here's some more info for you to follow :

     

    Digital cameras have essentially 3 arrays of light sensors (one tuned for red light, one tuned for blue light, and one tuned for green light). Yes some cameras do it differently (e.g. some have 2 green sensors...), but I'm trying to simplify and generalize in order to make a point.

     

    Each sensor records the strength of light at the frequency (hue) it is tuned for, and the values for all sensor arrays are what's stored as raw data.

     

    So one could also think of raw data as being 3 "grayscale" images, which must be mapped to colors we can see...

     

    Adobe's algorithms and Lightroom's camera calibration profiles are what dictate how the raw data is mapped to said colors.

     

    Of course there are numerous other potential color conversions/interpretations that involve the Lightroom colorspaces, and monitor (or print) profiles which dictate how those colors will appear to us, on screen (or on paper), (which is why color management/control is such a can of worms), but the in-camera colorspace has no bearing on any of this.

     

    Cheers,

    Rob

     
    |
    Mark as:

More Like This

  • Retrieving data ...

Bookmarked By (0)

Answers + Points = Status

  • 10 points awarded for Correct Answers
  • 5 points awarded for Helpful Answers
  • 10,000+ points
  • 1,001-10,000 points
  • 501-1,000 points
  • 5-500 points