Luminous Landscape Forum
Raw & Post Processing, Printing => Other Raw Converters => Topic started by: NigelC on June 29, 2009, 06:17:33 am
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I've encountered a strange problem. My raw shots are in Adobe RGB (1998). I have been viewing the files in DPP using the option to show jpeg and raws as one file. When use the command Import into Photoshop, Photoshop tells me the file has an embedded profile which is sRGB - when I check the shooting info in DPP it confirms the space is Adobe - is the action of merging the raw and jpeg doing something here?
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I've encountered a strange problem. My raw shots are in Adobe RGB (1998). I have been viewing the files in DPP using the option to show jpeg and raws as one file. When use the command Import into Photoshop, Photoshop tells me the file has an embedded profile which is sRGB - when I check the shooting info in DPP it confirms the space is Adobe - is the action of merging the raw and jpeg doing something here?
Have you tried just importing a pure Raw file with no JPG? I'm wandering if the attached JPG is 'forcing' sRGB colour space in this scenario.
I import pure RAW (no JPGs attached) from a 5DMark 2 using what starts out as Adobe RGB but because I use either Lightroom or DXO I am able to render the raw files into ProPhoto RGB in Photoshop.
Alternatively, try bypassing DPP and import directly into photoshop (provided you've got the right RAW converter for the file) What camera are you using?
Hope that helps.
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Have you tried just importing a pure Raw file with no JPG? I'm wandering if the attached JPG is 'forcing' sRGB colour space in this scenario.
I import pure RAW (no JPGs attached) from a 5DMark 2 using what starts out as Adobe RGB but because I use either Lightroom or DXO I am able to render the raw files into ProPhoto RGB in Photoshop.
Alternatively, try bypassing DPP and import directly into photoshop (provided you've got the right RAW converter for the file) What camera are you using?
Hope that helps.
I was using DPP because I've got a huge number of files I need to show as prof thumbnails and the DPP contact sheet option works better for me than Photoshop. Also, for something quick and dirty, applying a Portrait picture style to the raw file gives me a better result than I can get in ACR/PS for kids portraits. Camera is 5D (Mk1)
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Have you tried ACDSee pro 2.5? It does contac sheet printing, and it has replaced Bridge, LR2(I process in C1), and Explorer for me.
might be worth a look. I use it
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when I check the shooting info in DPP it confirms the space is Adobe - is the action of merging the raw and jpeg doing something here?
Tools --> Preferences --> Color management
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I've encountered a strange problem. My raw shots are in Adobe RGB (1998).
Raw files are in the color space of the camera. If you are shooting raw and set the camera to aRGB, the preview shown on the LCD and the histograms are from a JPEG rendering of the raw file into the set color space, but the raw data are not affected and the raw file is merely tagged with the color space set on the camera.
The raw converting software from most camera makers read the tag and render the raw image into the specified color space. However, the color space can be overridden. Most third party converters, such as Adobe Camera Raw, ignore the color space tag as well as most of the other camera settings except for white balance.
Bill
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If you are shooting raw and set the camera to aRGB, the preview shown on the LCD and the histograms are from a JPEG rendering of the raw file into the set color space...
What's the gamut of your typical camera LCD? 40% of Adobe? Even less?
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What's the gamut of your typical camera LCD? 40% of Adobe? Even less?
The gamut of the LCD is undoubtedly rather small, but this is largely irrelevant since few experienced users use the LCD to assess the relative quality of the image. The histograms and blinking highlights are more useful in determining exposure and clipped color channels and they are affected by the chosen color space and tone curve.
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I've encountered a strange problem. My raw shots are in Adobe RGB (1998).
What do you mean your Raw shots are in Adobe RGB (1998)? Raw has no color space.
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The DPP program is embedding it's working space color profile when you choose Transfer to Photoshop. For my particular setup it transfers the file as a TIFF and not RAW.
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What do you mean your Raw shots are in Adobe RGB (1998)? Raw has no color space.
Digidog,
Old dogs apparently do not learn new tricks
Bill
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Old dogs apparently do not learn new tricks
WTF does that mean?
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What do you mean your Raw shots are in Adobe RGB (1998)? Raw has no color space .
A few days ago I was surprized when reading this:
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How is having the data in the camera color space beneficial? You're exporting a output referred rendered image, presumably for further editing in Photoshop, so why not be in a well behaved RGB working space?
So, which one was a slip of tongue?
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So, which one was a slip of tongue?
None, I suppose. Camera color space is something different than the nonexisting "RAW color space".
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WTF does that mean?
Eric Walowit, Thomas Knoll and Chris Murphy (http://luminous-landscape.com/forum/index.php?showtopic=22471&view=findpost&p=168050) all think that a raw file does have a color space. When asked by you, "Does a raw file have a color space?", these well recognized authorities responded:
Walowit: "Fundamentally, absolutely YES,..."
Knoll: "The fact that a mosaic array is “grayscale” is a red herring in this argument. An early processing step fills in the missing values, and you have a 3 or 4 channel image as a result. For most cameras, if you just “assign” a working space RGB profile, you get a recognizable color image as a result, so it certainly seems like a color space."
Murphy: "So yes a camera (and thus a Raw file) has a color space."
So, there does seem to be a learning problem or stubborn denial.
Bill
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So, which one was a slip of tongue?
Neither. The Raw file is just that, the question was, what's the "color space" (certainly NOT Adobe RGB (1998)).
Once its no longer Raw, its rendered (output referred), it can (should?) be in a well behaved editing space like Adobe RGB (1998). So much depends on when and where in the process you refer to the data (Raw, scene referred or output referred).
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Camera color space is something different than the nonexisting "RAW color space"
Of course "raw color space" is always camera specific, there is no generic raw color space. When I say "raw color space", then I mean the color space of the camera, which created that raw file.
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When I say "raw color space", then I mean the color space of the camera, which created that raw file.
But the real, native color space of the camera may change every time you make a picture. And camera profiles are describing the camera behavior only in synthetic circumstances, so we can't really say that camera profiles are RAW profiles. We have different camera profiles for different occasions - for example modern Nikon Cameras have 9 different camera profiles, and each of these profiles has 20 variants for different illuminants - that makes 180 camera profiles! And in my opinion we can't say that any of these profiles is a "real RAW profile".
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But the real, native color space of the camera may change every time you make a picture.
Certainly changes with different lens and filter combinations.
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Certainly changes with different lens and filter combinations.
...and - what's most influencial - with different light.
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But the real, native color space of the camera may change every time you make a picture
The color space of the camera is given by the spectral responses of the sensels, thus it is fixed.
camera profiles are describing the camera behavior only in synthetic circumstances, so we can't really say that camera profiles are RAW profiles
What "camera profiles" do you mean? There is no generic camera profile; the profiles are raw processing specific. The same camera can be described by different profiles.
For example what is synthetic in ACR's camera profile relating to a specific camera?
We have different camera profiles for different occasions - for example modern Nikon Cameras have 9 different camera profiles, and each of these profiles has 20 variants for different illuminants - that makes 180 camera profiles! And in my opinion we can't say that any of these profiles is a "real RAW profile"
1. There is no point to distinguish between "camera profile" and "raw image profile". The raw image data is the incarnation of the camera's image characteristics.
2.These are neither "raw profiles", nor "camera profiles"; they are a combination of camera profiles and custom transformations. I don't know how to name them. The same with Adobe's profiles, particularly the DNG profiles.
Anyway, think of this: one can create such colors with these profiles, which are not reproducable by the camera (like "false colors"). Do you think, that these profiles really expand the gamut of the camera?
Certainly changes with different lens and filter combinations.
Do you agree, that the effect of lens and filter is equivalent to changing the illumination? (The same filter could be on the lamps!)
In effect you are saying, that the camera's characteristics depend on the illumination. This is equivalent to stating, that the camera's characteristics depend on the depicted objects. Do you think that the camera's color space is narrower when capturing a checker board than when capturing a colorful scenery?
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Interesting ... I guess it depends on whether the "camera" is the sensor ... or the sensor + the rest of the junk like the lens ... no?
But I see your point.
I guess it is easiest to think of the spectral response characteristics of the sensor as the base upon which all else is built and call that the native "space" of the camera.
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The color space of the camera is given by the spectral responses of the sensels, thus it is fixed.
The spectral responses are lens, filter, and illuminant dependend. The color space of camera will be different every time you'll change one of these factors.
What "camera profiles" do you mean? There is no generic camera profile; the profiles are raw processing specific. The same camera can be described by different profiles.
For example what is synthetic in ACR's camera profile relating to a specific camera?
The illuminant it's counted for.
1. There is no point to distinguish between "camera profile" and "raw image profile". The raw image data is the incarnation of the camera's image characteristics.
2.These are neither "raw profiles", nor "camera profiles"; they are a combination of camera profiles and custom transformations. I don't know how to name them. The same with Adobe's profiles, particularly the DNG profiles.
Anyway, think of this: one can create such colors with these profiles, which are not reproducable by the camera (like "false colors"). Do you think, that these profiles really expand the gamut of the camera?
I think, that all colors created with these profiles are "false colors" - the only way to make real "RAW profiles" is to make on-the-fly profile for each RAW image. It would be possible to make such profiles if we had spectral sensitivity of camera+lens+filter and the spectral properties of the scene.
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But the real, native color space of the camera may change every time you make a picture. And camera profiles are describing the camera behavior only in synthetic circumstances, so we can't really say that camera profiles are RAW profiles. We have different camera profiles for different occasions - for example modern Nikon Cameras have 9 different camera profiles, and each of these profiles has 20 variants for different illuminants - that makes 180 camera profiles! And in my opinion we can't say that any of these profiles is a "real RAW profile".
Carrying your argument to its logical conclusion via the process of reductio ad absurdum, then we could not render any raw file since we would likely not have the correct profile. An ICC camera profile made by various profiling software using a multicolored target such as the Color Checker SG usually employs lookup tables and is useful only under carefully controlled conditions such as might be found in a reproduction studio. For general use in field photography such profiles are not all that useful and a more general method is needed.
The approach taken by many raw converters such as DCRaw and Adobe Camera Raw is to use a 3 x 3 matrix conversion to convert from your non-existent camera space to CIE XYZ. Chapter 6 of the Adobe DNG specification, Mapping Camera Color Space to CIE XYZ Space, describes how this done. Since the color filters in a Bayer array sensor are not linear across the range of the human retinal cones, the result will only be a first order approximation. See this quote from Thomas Knoll (http://forums.adobe.com/message/1206990#1206990). Denying the existence of a "camera" space negates this approach. Also, trying to differentiate between a raw file space and the camera space is only obfuscation. As Gabor explained, the space in a raw file is that of the camera from which it was derived.
The newest DNG profiles also provide hue/saturation mapping tables. Accurate color may be very difficult to obtain with this approach, but pleasing colors are usually achieved.
Bill
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The spectral responses are lens, filter, and illuminant dependend. The color space of camera will be different every time you'll change one of these factors
One could adopt this approach, but it would not be very useful, for a raw processor would have to create lots of profiles for every camera. How many combinations of temperature and tint do you think would be required? For example ACR supports temperature from 2000 K to 10000 K in 50K steps, that is 161 different values, and the tint can be any integer from -150 to +150. That is 161*301, 48461 different combinations.
It is much more useful to describe the sensor's response on its own and account for the illuminant (including lens and filter) through white balancing, an independent step.
The illuminant it's counted for
No, it is not. The ACR camera profile describes the color transformation between the camera's color space and CIE XYZ relating two illuminants; the actual transformation will be interpolated based on the actual illuminant relative to the two specified illuminants. The two illuminants are typically "Standard light A" (incandescent) and D65 (6504 K natural daylight), but a program converting a native raw file in DNG can choose different basis illuminants (this occurs with the raw files of certain MFDBs).
It is permitted to specify only a single illuminant, but that is useful only if the transformation is specified based on that particular illuminant; this is the normal case with scanners but not with digital cameras, though some MFDB raw->DNG converters require the specification of the actual illuminant and write the transformation fixed for that illuminant (in effect they anticipate the white balancing).
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Since the color filters in a Bayer array sensor are not linear across the range of the human retinal cones, the result will only be a first order approximation.
That's exactly what I meant. I don't deny the existance of camera color spaces, I only think they are more or less virtual, and wouldn't name them "RAW color spaces". Each RAW file has a "real" color space, that is a unique result of camera's spectral sensitivity and scene's illuminant spectra combination. As long as we don't know the spectral properties of scene's light, we can't talk about a "real" RAW color space.