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Thread: some questions for ProPhoto color space

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    some questions for ProPhoto color space

    Hi,
    I used to use Adobe RGB(1998) profile to work with image files(output files from capture one, master retouching files in photoshop, and final files for clients...).
    I'm planning to start working with ProPhoto color space for the output files from capture one and master retouching files in photoshop.

    Are there anything I need to be careful about working with ProPhoto profile?

    Here are some points I've already heard...
    1. It's safer to work... in 16 bit mode.
    2. Don't push too much in Saturation with ProPhoto profile.
    3. Don't send out the ProPhoto profile embedded files to clients unless...

    And what happens if I work with the images(ProPhoto embedded) in the Adobe RGB 1998 working space(photoshop color setting)? Should I work... in ProPhoto working space instead(photoshop color setting)? What would be the differences?
    Thanks in advance!

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    Re: some questions for ProPhoto color space

    If using ProPhoto, ALWAYS, ALWAYS, ALWAYS work in 16 bit. That space is huge & if you work in 8 bit you are almost guaranteed to have posterization.

    I tend to edit in ProPhoto after opening up RAW files because that way I can archive using the all the colors delivered to me by the camera, even though I might not be able to print or even see it all on my monitor. It "future proofs" your images. Smaller spaces throw away info that can never be recoverd.

    The way I Set up Photoshop is (under Color Settiings) for each of the standard RGB working spaces, such as Adobe RGB, ProPhoto, sRGB, to set the Color Management Policies to "Preserve Embedded Profiles". That way you will always open the file to the same working space as it was embedded with when it was created. You can alway convert it to another space if you wish, but that way you don't get any undisired changes.

    If you were to view a photo with an embedded ProPhoto profile in an Adobe 98 space, that photo will look desaturated & flat. Not pretty!

    When sending out a file, you need to know if the person you are sending it to is has any knowledge of profiles, or how to use them. The operators of most consumer photo labs probably don't have a clue what a profile is or how to use it. You are therefore relying on how the equipment they have is set up. Some may be profile aware, some may not. When sending out a file to a generic photo lab, their equipment is most likely set to assume the profile is sRGB & may not even look at any embedded profile.

    On on the other hand, a professional stock photo vendor probably will TELL YOU what profile they want the file in.

    For cheap printing, I use Costco. Amazingly enough, you can go to drycreekphoto.com & download printer profiles for Costco printers in locations throughout the U.S. They are updated every 6 months or so. They are not perfect, but not bad either -- and certainly better than sending them an sRGB file. For the Costco wet printers, I embed the printer profile even though I don't think the printer looks as that info -- at least that way if I open up the file I know what my intended destination was. For the large "Poster Prints" that use the Epson inkjet printers, the instructions at Dry Creek Photo is that you should convert to the printer profile, but NOT embed it.

    I hope this helps!

    --Alan

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    Re: some questions for ProPhoto color space

    Thanks for the reply!!
    But I'm curious about your statement.... "If you were to view a photo with an embedded ProPhoto profile in an Adobe 98 space, that photo will look desaturated & flat. Not pretty!"

    That's because I heard that the usual monitor( in my case_ Lacie321) would not show the colors which is outside of Adobe 98 profile( but inside of ProPhoto profile), meaning that there would be no visual differences between working with the ProPhoto embedded files in Adobe 98 space and working.... in ProPhoto space....

    I might be wrong...

    Thanks!

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    Re: some questions for ProPhoto color space

    My statement "If you were to view a photo with an embedded ProPhoto profile in an Adobe 98 space, that photo will look desaturated & flat. Not pretty!" is NOT in reference to your monitor profile & working space.

    Try it yourself. Take any photo & convert it to ProPhoto (if it isn't already.) Then go to Edit, Assign Profile, and select Adobe RGB (1998), or any of the other color space that is much smaller than ProPhoto (such as Apple RGB or sRGB) & you immediately see the image get washed out.

    The monitor & it's profile are yet ANOTHER separate & independent step in the way your system manages color.

    Bruce Fraser, in his invaluable (now somewhat outdated) Photoshop book said that "Rendering to the monitor is alway relative colorimetric, so colors in the working space that lie outside the monitor gamut get clipped to the nearest equivalent the monitor can display." That means that while the monitor won't display all the colors that MAY be in an image that's ProPhoto RGB, it won't generally desaturate the whole image -- only colors outside the montor space get clipped.

    I hope this clarifies...

    --Alan

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    Re: some questions for ProPhoto color space

    Still.. a little confusing...
    But many thanks!!

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    Re: some questions for ProPhoto color space

    Quote Originally Posted by studio347 View Post
    Hi,

    And what happens if I work with the images(ProPhoto embedded) in the Adobe RGB 1998 working space(photoshop color setting)? Should I work... in ProPhoto working space instead(photoshop color setting)? What would be the differences?
    Thanks in advance!
    There is no point in "embedding" the ProPhoto space in a file if you are going to work on it in Photoshop in AdobeRGB. Once you clip the colors into the AdobeRGB space, they are gone ... even if the image is "pro photo" your working space palette sets the rules.

    If the file is a ppRGB file, you have two choices, to work in ProPhoto (and has been mentioned only 16 bit) or to convert the file to the AdobeRGB space when opening it in photoshop and then work in that space. If you have all your mismatch warning settings turned on in Photoshop color settings, you will get dialog boxes that ask you what to do.

    If PS is set up as aRGB for the working space, the mismatch dialog will ask you whether to use the embedded profile, or convert to the current working profile. If you select use the embedded profile, that basically tells PS to use the embedded profile (in this case ppRGB) for the working space for that document.

    Best practice is convert from raw into 16bit ppRGB, use ppRGB as your working space in Photoshop, then convert to the appropriate "output" space for your purposed files, such as to the printer or 8bit sRGB for the web.
    wayne
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    Re: some questions for ProPhoto color space

    Quote Originally Posted by studio347 View Post
    Still.. a little confusing...
    But many thanks!!
    My advise to many I teach is to follow and trust the steps of good color management, don't worry so much about the whys and hows. If applied correctly it works, but is confusing and the logic behind it isn't readily apparent unless you study and understand the concepts behind it.

    One of the most "confusing" points is the "working" space and "embedded" space .. .important to realize those spaces are theoretical spaces that in essence simply supply a reference for the colors as they are stored in the file. The file itself is never "viewed" in one of those spaces, they colors are always converted to an output space before being viewed. So the real difference is how large the spaces are, which determines how many colors the image can contain. thus the need for ProPhotoRGB for modern cameras ... adobeRGB just doesn't define enough colors.

    You may find a little time reviewing the information here might be helpful.

    http://www.cambridgeincolour.com/col...t-printing.htm
    wayne
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    Re: some questions for ProPhoto color space

    There is a well illustrated and relatively simple explanation at http://www.luminous-landscape.com/tu...oto-rgb.shtml#

    Best wishes,

    Ray

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    Re: some questions for ProPhoto color space

    Thanks Wayne & Ray for your inputs. I particularly like Wayne's comment:

    "Best practice is convert from raw into 16bit ppRGB, use ppRGB as your working space in Photoshop, then convert to the appropriate "output" space for your purposed files, such as to the printer or 8bit sRGB for the web."

    Thanks again,

    --Alan

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    Re: some questions for ProPhoto color space

    Quote Originally Posted by studio347 View Post
    Hi,
    I used to use Adobe RGB(1998) profile to work with image files(output files from capture one, master retouching files in photoshop, and final files for clients...).
    I'm planning to start working with ProPhoto color space for the output files from capture one and master retouching files in photoshop.

    Are there anything I need to be careful about working with ProPhoto profile?

    Here are some points I've already heard...
    1. It's safer to work... in 16 bit mode.
    2. Don't push too much in Saturation with ProPhoto profile.
    3. Don't send out the ProPhoto profile embedded files to clients unless...

    And what happens if I work with the images(ProPhoto embedded) in the Adobe RGB 1998 working space(photoshop color setting)? Should I work... in ProPhoto working space instead(photoshop color setting)? What would be the differences?
    Thanks in advance!
    ProPhoto RGB is the only colorspace that is large enough to fully enclose the potential output of up to 16bit imager sensors with editing room.

    - NEVER work in anything but 16bit with ProPhoto RGB. It is too large a colorspace to be characterized in an 8-bit per component pixel map.

    - Clients never want ProPhoto RGB files, or at very least should ask for them explicitly. Most production houses who are going to edit files today are set up for 8bit TIFFs in Adobe RGB (1998) as that colorspace was designed to model the four-color CMYK prepress printing machines. Many only want to do light finish editing and 8Bit JPEGs at max quality and either sRGB or Adobe RGB are fine.

    - When converting to 8-bit per component for clients from ProPhoto RGB, first convert to Adobe RGB, then down sample to 8bit per component. Use a gamut checker if you want to be critical ... sometimes the choice of relative vs perceptual intent can become critical.

    That's about it. I work in ProPhoto RGB all the time, have been for several years, and aside from mistakenly trying to apply it to an 8-bit per component image file, have never had a single problem doing so.

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    Re: some questions for ProPhoto color space

    Thanks for all the infos. As a photographer, obviously I have a limited ability and time to understand all the scientific background for a workflow. But it's a good feeling ... to know the behind story of some important aspects in the workflow...

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    Re: some questions for ProPhoto color space

    Notes:

    I have always been keen on keeping the colour data quite well contained but not swimming in the colour space. It is very poor practice of s/w not to permit custom spaces, one still sees this problem today.

    I have never been enamoured of the saturation model as deployed in Adobe products. Perhaps they also feel it is problematic to some degree, hence 'Vibrance' in LR.

    I use Joseph Holmes spaces where possible, but for apps that are authoritarian about their space permissions - ProPhoto, to start with. I import into PS into my JH spaces.

    The color variants are extremely effective as an alternative colour 'handler'.

    I also recommend users pay close attention to luminosity masks in PS - Tony Kuyper offers (for a modest sum) very effective action sets for segments of the the tone range. I use these for a range of purposes, including:

    . boosting midtone colour (colour is a midtone phenomenon).
    . finetuning contrast in different areas of the tone range, so for example, if you have a lot of data tightly compressed (little contrast) on the histo, you can choose the appropriate tone range luminosity mask and use a blending mode of 'soft light' or 'hard light' to spread the data open a little.
    . boost shadows using 'screen' blend mode.
    . ease off highlight presentation with 'multiply' blend mode

    You can use a grad or brush to fine-tune further.

    The interaction of colour and contrast determines the effect of the final image very often. Fine tune individual colours using 'Selective colour' and 'Hue/Saturation'.

    For further explanations of colour spaces, see these references, a few years old now but I find them relevant >

    Joseph Holmes - About RGB Working Spaces

    Joseph Holmes - About the Spaces and Sets

    Joseph Holmes - Profile Testimonials

    I use JH's DCAM3 (digital) and ChromeSpace100 (E6 film).

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    Re: some questions for ProPhoto color space

    Oh, 16 bit always for editing/storage for later editing, 8 bit for output, last stage.

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    Re: some questions for ProPhoto color space

    Philip, I am about to pick up a colour space from Joseph Holmes, but am trying to learn my way around the concepts before I do that, so I may choose the best one. I am also leaning towards DCam3.

    First of all, I understand that Adobe RGB is too small to encompass the colours coming from most modern cameras, and also too small for the gamuts of modern (Ultrachrome here) printers, so I will avoid Adobe RGB.

    Secondly, I understand that while ProPhoto RGB is big enough for those two purposes, it is *so* large that the data points in it get stretched unreasonably far apart, and that heavy editing (which I sometimes do) can cause posterization, even in 16-bit workflows. I also understand that the tone curve is not ideal for our purposes, i.e. the data will need massaging.

    Thirdly, I understand that using Holmes' colour space variants is a better way to tune saturation than yanking sliders in almost any software (all?).

    But I still don't understand everything... I would also be happy to hear from Jack, since I see that he contributed valuable information to a ton of colour space/profile threads in various forums around 2006

    My questions:

    1) First of all, Joseph Holmes recommends to take the raw from the camera, and *convert* it to one of his spaces. But where is it coming from? I tag my NEFs with Adobe RGB, since my D800 doesn't offer anything better, to my knowledge, and I hope that the image doesn't get squeezed through this space on its way to larger accommodations. Does the software have a D800 space/profile which it converts from? What happens to the Adobe RGB tag in this step, does it get ignored?

    2) Is there any way to use these profiles with Lightroom, or to have an equivalent workflow? I understand that while Photoshop can use ICC profiles/spaces, Lightroom cannot, because the Lightroom developers are wiser and thought that ICC was a bad idea (why?). I just switched from Aperture 3 to LR4, but I might yet switch back, as I am not all that enamoured with LR. Alternatively, I might switch to some other software to do my library management, and then use C1 or RPP or something to do my processing. Recommendations?

    I think I have more questions, but I guess I will stop here for now. My eventual goal is to more or less understand what happens to my colours from one end to the other, and hopefully to use this knowledge to cure my D800's tendency to render fire engine reds as orange when lit by strong sunlight.
    Carsten - Website

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    Re: some questions for ProPhoto color space

    Oh, one last thing I "know", before I forget:

    As far as I understand, it is best to leave the photo in the working space and let the printer driver do the conversion. If you convert to sRGB or whatever before printing, you still run the risk of clipping. Additionally, I think I read that depending on whether your working space is table- or matrix-based, it may not be possible to convert using perceptual metrics, whereas this apparently always works with the printer drivers.

    An alternative would apparently be to convert directly to the printer profile, and print without colour management.
    Carsten - Website

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    Re: some questions for ProPhoto color space

    After several more days of research, I can probably answer my own questions now:

    1) The Adobe RGB tag in a raw file is ignored, and the software uses its own camera profile to convert from.

    2) No. Lightroom uses Melissa RGB as its workspace, which is basically the gamut from ProPhoto RGB combined with the tone curve from sRGB. Using this tone curve helps preserve shadow detail. The gamut is still much larger than DCam3, but with 16-bit processing, the question is if most people will ever see that. I have still not seen a good comparison to judge for myself.

    I did see a good comparison between Magne's Canon 5D Hi-Sat and DCam3 +20 profiles, and they are practically identical in all images except for one, and there the difference was more subtle than I care about. But of course, this may not be the case with normal saturation tools compared to DCam3.

    I can hear the crickets in here
    Carsten - Website

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