Color management for photographers: a primer


Color spaces, from Wikimedia Commons; reused under a Creative Commons license. Image by Cpesacreta. What is clear here is that none of the common color spaces or reproduction methods can display the entire visible spectrum.

Starting from the start, a colour space defines all of the possible tones and hues that a single pixel may take. The values may take either a RGB value or CMYK value; the set of three numbers represents the amount of each colour present from a scale of 0-255, which gives 256 possible tonal values for each colour (red, green, blue or cyan, magenta, yellow and black). Combining every possible permutation of these gives you 16.7 million possible different colours for RGB. Note that you don’t get 4.3 billion colours for CMYK, because the K (black) value controls the overall brightness and density rather than contributing another possible hue to the mix.

The reason why we have different colour spaces is because they define the limit of reproducible tones for a particular reproduction method – be that screen, web, print, or TV transmission. The most commonly used colour spaces are either a type of sRGB or newsprint CMYK; both of these actually offer very limited reproduction potential. Many of you will notice that most images you see on the web, or in print, are lacking in depth and tonal subtlety; this is simply because the desired tone simply cannot be reproduced, and as a result lands up defaulting to the nearest possible colour value – which is obviously not going to accurately represent the original image. When a colour goes outside the possible range, this is known as gamut clipping. Some of the better proofing software can be configured to display a warning when this occurs; Camera Raw shows a small warning triangle in the upper-right near the histogram.

For photographers, the important colour spaces you need to be aware of for digital display are Adobe RGB, sRGB and ProPhoto RGB. For print, it’s whatever variant of CMYK your printer uses. Let’s start with the former. Adobe RGB is the most common wide-gamut colour space available; almost every camera today – even compacts – has the option to output in this colour space by default – use it. sRGB is a limited, mostly web-safe gamut that varies slightly depending on the standard; one camera maker’s sRGB won’t be the same as another, and the sRGB displayed online will be different yet again – possibly depending on the browser, or your system settings, or any one of many other factors. Avoid this wherever possible. The final RGB – ProPhoto – provides the widest of all gamuts; however, most monitors aren’t capable of displaying the majority of the possible colours, and few web browsers support it. I’m going to leave covering CMYK until the section dealing with print.

Although the tonal limitations of each colour space depend very much on the specific colour space themselves, it’s safe to say that in general, you’ll see the difference between Adobe RGB and sRGB most prominently in the blues and greens. There’s a particular shade of sky blue that seems to be nearly impossible to reproduce in sRGB, for instance. CMYK has similar restrictions to sRGB, but biases towards cyan instead of green and blue; overall, it lacks the vibrance and saturation that RGB can deliver – unsurprising given that the constituent colours are not red, green and blue! CMYK is used only for print proofing and is never found in camera or monitor; this is because the native components of these devices are formed of RGB photosites or pixels.

The observant of you will have noted that 256 tonal values represent 8 bits of information per colour channel. So why do we bother with 14 bit raw files, and working in 16 bits? Simple: although our output may always only be 8-bit, the amount of information we have going in affects the amount of work we can do to a file before we start to see posterisation (separation of areas into distinct blocks of colour with no tonal variation or smooth transition between adjacent zones). If we have 256 input values, do some contrast adjustment (effectively, ‘stretching’ the histogram) – we might now make some of the levels cover adjacent levels, resulting in only say 150 truly distinct tonal values for a particular channel. Most of the time, software will cover these ‘steps’ reasonably well; however, the reality is that you will see some posterisation. Working in a 16-bit colour space – with 65,536 tonal values per channel – avoids this problem mainly because we can’t actually achieve this many distinct tonal values through most reproduction methods; everything is effectively down sampled before output. Make sure you have your editing software convert any files in other colour spaces to the working colour space, too.

In-camera, the best option you have for maintaining accurate colour is to shoot RAW, Adobe RGB and whatever the highest bit space your camera offers; for the current batch of Nikons that would be 14-bit NEF, Adobe RGB, lossless compressed or uncompressed. (Lossless compressed only discards information in portions of the tonal register that aren’t being used or are adjacent duplicates, not any of the actual image data). Any time you’re shooting JPEG, you’re limited to 8 bits – and every file is compressed; avoid shooting JPEG unless you absolutely have no choice (A non-compressed JPEG is effectively a TIFF or bitmap). After being used to the tonal elasticity of of manipulating a good RAW file, you’ll be surprised at just how fast a JPEG will clip or posterise when manipulated – it’s one of the reasons that I almost always avoid buying a camera until there’s full RAW support for it through my usual workflow (ACR>PS). And it’s also important to note that RGB channel histograms and overexposure warnings are important: once a channel clips, it’s gone for good, especially with JPEG files. Although most raw converters will allow for some interpolation of surrounding tonal information to recover and reconstruct some highlight data, it won’t be that accurate.

All of this care during capture would be useless if not maintained during the postproduction process – that’s the importance of your screen workflow. Firstly, you need to have a good monitor that’s capable of displaying a wide gamut; the best of today’s bunch (Eizo, some NEC, Apple Cinema Display) are capable of covering almost all of the Adobe RGB gamut; if you’re serious, this is the kind of monitor you want. Secondly, it needs to be calibrated – i.e. ensuring what you see on screen accurately represents the actual data. The Monitor Calibration Utility for Apple (under System Preferences, Displays) is actually pretty good at this if you do all of the steps properly – a handy tip is to have an image which you’re familiar with open in another window while you run the wizard to ensure that the end output looks accurate to you. For Windows users, you’re recommended to invest in a Spyder or something similar – this generates a profile that the monitor then uses create its display output.

The next step along the chain is output: what are you going to use the image for? If it’s print, save as a 16 bit uncompressed TIFF; this will give the printer as much information as possible to work with when performing the RGB to CMYK conversion. I don’t actually recommend performing this conversion yourself unless you have the exact colour profile your printer is going to use, otherwise you might land up with some strange hue shifts. If it’s for screen or web use, then a jpeg is fine – most viewers are not going to have the right equipment to view the full gamut anyway; thus it’s better that you run a test proof under as close to actual viewing conditions as possible. I wouldn’t advocate going to sRGB unless you know that’s the only possible output; your best choices these days are Safari and Firefox – both are available for Windows and Mac. Similarly, ensure that your web hosting service preserves as much of the colour information as possible; the only one I know of that doesn’t convert things to sRGB is Flickr. Facebook et al are absolutely horrible – not only do they compress the hell out of the image, but they also shift everything into a very restricted web-safe sRGB that makes things appear both tonally blocky yet ‘coarse’ at the same time, due to the compression. Do NOT use Facebook to display images unless you have no choice, don’t care, or didn’t have the tonal information to begin with (smartphones, for instance) – everything just looks bad.

Printing is a whole article unto itself, but I’m going to touch on it briefly here: the main disconnect between the print workflow and the capture workflow is colour space; screen viewing involves an additive method where R, G and B are mixed together to make the desired colour; print uses C, M, Y and K inks subtractively to create colour. The reason for this is simple: pixels are backlit, prints aren’t. You’re dealing with reflected light off the print medium as opposed to transmitted light. Although this conversion process keeps improving, the mapping isn’t perfect and there still remain portions of the Adobe RGB gamut that can’t easily be reproduced in print. Part of this is due to the subtractive method; part of it is due to the fact that ink drops are either there or they aren’t – to create the illusion of tonal variation, printers use very, very small drops and dithering or half toning to leave white space between the dots. Note that print DPI is not the same as screen DPI – one pixel may be represented by anywhere up to 12 dots of ink! By far the best option for printing is to ensure your RGB output file is as accurate and full of information as you can manage; then find yourself a competent printer. I’m not going to get into self-printing – suffice to say that I did try, but between the wasted test prints, the clogged heads, the cleaning cycles…it simply wasn’t economically feasible for me to maintain my own printer.

There’s one final thing you have to take into consideration when an output image is being viewed: the effect of ambient light. It’s less important for devices that supply their own light – LCD panels, for instance – but it still matters because ambient brightness might overwhelm the panel and make colours appear dull or washed out. It’s far more critical for print viewing; the colour temperature of ambient light will affect the perceived white point, as well as the light reflected off the print itself. This causes toning or shading of the print; a good print master will adjust the yellow and blue components of an image for the intended display location; for instance, under tungsten light you have to remove some yellow component and/or increase the blues slightly as the light itself will provide that; the opposite is true for LED lighting. This is why all critical print proofing should be done in daylight – or under a daylight (5500-6000K) source. There are special daylight spectrum fluorescent tubes available for this purpose.

You’ll notice that I haven’t said anything about black and white workflow – it still matters, though less so. Assuming your printer can create a pure black and white without any hue shifts, then the important part is to check your grayscale space – this works in a similar manner to colour spaces, but controls the gamma of the image rather than the actual range of possible tonal values. This is critical to ensure that the resulting output image has the right density.

I’m going to finish with a final note on my own workflow. I run a 15″ MacBook Pro, calibrated with the Monitor Calibration Utility. I shoot 14-bit lossless compressed RAW in Adobe RGB on my D800E, M9 and OM-D; the RX100 is JPEG-only for the moment (Update: now supported by ACR/ LR as at October 2012). Files are opened in Adobe Camera Raw for initial adjustments (even JPEGs) before conversion to the working file format in Photoshop; I keep everything in 16 bit Adobe RGB until output. My web output is 8-bit JPEG; everything else is 16-bit lossless compressed (LZW) TIFF, or Photoshop (depending on the use or client). I will do some CMYK conversions for clients if they can supply the working CMYK space; otherwise, if it’s print, I leave the conversion to my printer – he knows the output capabilities of his equipment far better than I do, and I’ve yet to be disappointed with any of his output. It’s important to note that although I’ll select the colour space that retains as much of the original tonal information as possible, there’s also no point in bloating files if the information simply wasn’t there to begin with in the first place; I’m not going to save a conversion from a 12-bit RAW file as a 16-bit TIFF because there simply isn’t that much information after manipulation; let alone a JPEG. These will be saved as 8-bit compressed TIFF files instead.

Although the colour management process can be daunting, it’s important to invest time in understanding it and get it right – you’ll find afterwards that your images look a lot more consistent, regardless of the display medium. MT

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Comments

  1. Ming,
    REALLY enjoyed this tutorial.
    Reading the above comments urged me to conduct a simple test. Nothing very scientific, but fairly accurate none the less. I took two exposures of my color checker passport under my studio lights (my D800 on tripod, no external lighting and same exact framing) one in ARGB camera setting and one in SRGB camera setting and then brought both images directly into ACR. To my surprise (and as you have been maintaining all along) the histograms were different! I did find that there were slightly higher levels of color in the ARGB file.
    Thanks for sharing your experience and really enjoy your work!

  2. So, if some-one is going to consider editing in Adobe RGB then they will need a monitor that supports Adobe RGB? This limits the field a lot e.g Eizo, NEC and a few others. I currently use a Sony RX100. For better colour I have two options: upgrade the camera to at least m43 format and stay with sRGB or upgrade the monitor and stay with the RX100 (shooting raw of course).

    In your opinion Ming, which option gives better colour for less effort / money?

    • Not quite. You need to have more input data than your output medium; ideally they should all be matched. So long as your display is better than your final medium, you’re fine. I use a calibrated 27″ Thunderbolt Display. I’ve never had any complaints about my color accuracy…

  3. Thank you for your explanation! I’m a bit confused though where the difference between the color spaces is, as RGB uses 16.7M colors so that both color spaces have that many colors to work with? My screen shows that many colors and is said to cover sRGB with 16.7M colors (LG IPS 234). Now, the Apple Cinema display which you said covers aRGB has just as many colors. Where is the difference?
    What’s more: I use a Panasonic G5, shoot raw and have the menu for color space set to sRGB. Nonetheless, in Aperture the file info tells me it’s aRGB. How come? Is it because for my camera, the color space is not “engraved” in the raw data? But if so: Why aRGB? Did Aperture decide on that?
    Aaah… help! It’s all so confusing…

    • 1. 16.7m colors is the theoretical maximum. What they display physically manages is down to the hardware and will always be less – take black for instance; most monitors can’t completely turn off a pixel or prevent neighbouring light spillage, so you never get 0,0,0.

      2. Chances are Aperture is converting it for you. There’s probably a color settings preference somewhere.

      • Ok, that makes sense… still, though – where then is the difference between the color spaces sRGB and aRGB if they both use the same amount of possible color values? Do they just use more or less of the possible maximum? And should I change the setting then since my screen can’t show aRGB correctly? I’ve never felt that any colors were off, though – not even in print (and I never calibrated nothing) (I know I should though)

        • They don’t. They represent possible output values. RGB has X number of colors. ARGB and sRGB display different amounts of those, so yes, more or less of the possible maximum.

          You should work in the broader gamut because even though your screen might not be able to display all of the colors, there may be visible shifts caused by processing processing affecting the colors you can see.

          • Ok thank you! So basically I just leave everything as it is :) Nice how things turn out sometimes :D I could consider getting a better screen one day, though…

  4. I am slightly confused. I shoot a mix of RAWS and jpegs, quick record shots in jpeg more important stuff in RAW. I used to set the camera to adobeRGB but after reading strong advise on other websites switched to sRGB. I didn’t know it made a difference to the in camera RAW so now I will switch back. My question is when sending the image for printing as a jpeg does it matter if its adobeRGB or sRGB? If the print shop converts it anyway I guess adobeRGB is better. Where does the issue of getting unexpected and dull results stem from, putting adobeRGB on the web? What if any is the disadvantage to working in adobeRGB? I switched to sRGB because I thought it would make my workflow consistent throughout but if the cost is possible colour clipping etc. then I will switch. Apologies for being a bit behind on this but I’ve only just found your site and what a great site it is, I have spent the last few days reading and enjoying viewing your photos.

    • It depends on your camera. It *appears* that with the Nikons at least, it does matter if you set ARGB or SRGB. Printing takes place after conversion to CMYK – there are no RGB printers – so there’s an additional conversion step involved in there. Ideally, you want to give them as much information as possible so they lose as little tonal values as possible in the conversion.

      Keep your workflow in as wide a gamut as possible. ProPhoto is ideal, but most monitors won’t even show the whole ARGB gamut let alone ProPhoto. ARGB is the most commonly supported wide-gamut space – and there are browsers like Safari (the only one, I think) that are color-space aware.

      • Ming, I still disagree with setting AdobeRGB in camera.
        I did some more research, and the RAW file is always recorded in the native colorspace of your camera (which is way larger than even AdobeRGB). The only difference of the setting will be that Nikon software will read it and set it’s default accordingly, but you could always change it later on.
        If you dig around a bit more in CameraRAW, you will find color profiles for all (RAW) supported Cameras. You can even load these into profile viewing software and compare for yourself.
        What I do agree with is to keep your workflow as wide gamut as your destination usage can use.

        Ian, it might matter which color space you send to your printing service. Some (cheap) printing services only process sRGB and if you send them AdobeRGB you will get subdued colors. Easiest way to check this is to send one picture two times to the printing service: once as sRGB the other as AdobeRGB and compare the results. If the colors of the AdobeRGB are washed out they do not support profiles and should be sent sRGB files. I had one printing service who uses an HP fine-art-printer but could only work with sRGB. Horrible results if you send him AdobeRGB.

        • Hmm, I’m now wondering if ACR is reading some tags from somewhere because the EXIF data clearly shows a different color space if you change it in camera, even if you shoot RAW. It’s hard to say if this affects the output color space or not – I’ve never shot RAW + SRGB for enough frames to be sure, so you may well be right.

  5. Why bother setting the colorspace when you shoot raw? Tools like Lightroom ignore it anyway and use their own color space (Melissa), and in PS it would be better to open the file in 16bit ProPhoto instead of AdobeRGB anyway.

    • Not true. Try shooting SRGB and ARGB with the D800, especially for scenes with large tonal variety and the results are noticeably different. ProPhoto is useful for editing but not for export because even the color aware browsers can’t display it anyway – ARGB is the most commonly used ‘wide’ gamut. It’s all a compromise, but what can you do?

      • radeldudel says:

        I don’t care about browsers, only about print.
        But I’m surprised about your opinion about the effect of color space in RAW and will give it a try.

        • Ah, then that’s a different question. A lot of my work – both for clients and personal stuff – ultimately ends up online, so it does matter to me.

          If there was no difference…why would they give you the option of SRGB or ARGB? :)

      • radeldudel says:

        Now that one is easy: The option is there because there is a difference if you shoot in JPG. It just does not matter in RAW, like so many other image options in camera doesn’t.

        • Agreed, but I’m quite sure it makes a difference in RAW too. It’s been a while since I tested this though. The other options in camera – like picture controls, for instance – make a difference to the RAWs too if you use NX2. Otherwise it just affects the preview image and metadata tags. I’m fairly sure the color space does affect the RAW file though.

      • NX2 will honor the switch and change the parameter. But you could as well just capture in sRGB and change the switch to adobeRGB in NX2 instead without any losses. NX2 uses all the metadata tags. Other Raw-Converters ignore them.

        If you don’t use NX2 but (eg) Lightroom, it won’t matter at all what color space you set in camera since metadata tags are ignored and the preview will only be used for a second while a real preview is rendered.
        I’d be very surprised if this made any difference. In RAW the sensor data is written without interpretation along with the settings you used for that switch. I’ll give it a try with some tone rich image though, but I’d be really surprised since this does not match the description of RAW imaging.

        Of course it will matter a lot in which color space you give your pictures to a printer, since sRGB cannot display some colors.

        • The other possibility is that your color preferences for PS might affect things – if the image is tagged as SRGB and you have ‘preserve existing color space’, then it will affect postprocessing latitude. Agreed that all of the non-NX based software disregards tags.

      • Well, we already agreed the color space being important in editing, and opening the file in a high-quality-way belongs to editing, not to image capturing. Not?

      • Of course, and thats why you shoot RAW. No use in shooting JPG and throwing most of the data away!

  6. Support for RX100 was added with LR 4.2….

  7. I have an issue with the Apple calibration script. Simply put, if you get close to an accurate profile it’s a fluke. Adobe realised this and stopped loading the adobe gamma utility years ago. The human eye is so easily fooled that it’s impossible to achieve consistent output. Not only is every set of eyes slightly different they also change with age and with the influence of our surroundings. A coliorimeter is accurate consistent and cheap with Spider models available for less than a hundred dollars. One in a thousand will get a fair profile using these scripts but it’s not something I’d recommend.

    http://flashgordonphotography.com.au/for-photographers-central-coast-wedding-photography/an-introduction-to-colour-management-for-photographers/

    Gordon

    • The accuracy of your profile definitely depends on your eyes and ambient light. But for those not doing color critical applications, or who do have the experience – it works fine. I’ve always done this and never had any issues with my output. Perhaps I’ve been consistently lucky 1/1000 times every time I calibrate my monitor…

      • If you are not using a hardware calibration device, you are kidding yourself. The human vision system automatically does “white balance correction”, that’s why fluorescent lights appears white to us despite being green in reality. You are still getting the results you want because you and your printer effectively have a “closed loop CMS”, i.e. your monitor and their printer are not calibrated to a standard, but they compensate for one another.

        It works as long as you always work with the same printer, but let’s say you have to send a print order a continent away in San Francisco for a gallery and don’t have the time to get proof prints made. Your results will be different because the SF printers don’t have the “Ming Thein’s eyeballed monitor profile” and thus cannot compensate for it.

        Given the expensive equipment you deal with, paying a couple hundred dollars for a Spyder (colorimeter) or better $450 for a Colormunki Photo (spectrophotometer) calibration system wouldn’t break the bank and yield much more controlled results. You wouldn’t try to eyeball what color gels to use on your flash heads in mixed lighting scenarios, you would use a color flashmeter.

        Just for laughs, I tried the Apple DIsplay utility to profile my new HP ZR30w (the backlight on my LP3065 failed after 5 years of loyal service). The results were even worse than the default profile, and far bluer than what the Colormunki yielded after calibration. If I color-corrected my images based on the default or Apple gamma-based profile, I’d end up with a yellow cast on my images when printed.

        • I send the files off to my current printer without me intervening in the print process. The results are identical when my clients do the same with their printers. The solution is to embed the profile in the file or attach it separately, in case there are any issues. There haven’t been, so far. And given the huge number of positive comments about my color and tonality, I don’t intend to change my workflow. Use whatever works…

  8. Btw, where do you do your prints?

  9. Dont you need an NEC screen to get accurate colors, as well as calibrating it and profiling the printer, etc. ad infinitum? I’d spend hours in PP trying to perfect the colors I’d seen earlier that day, but still the final print rarely turns out like you wished it would. Oh the joys of the digital workflow! I’d much rather develop my own b&w and color film (with a Jobo processor) and do my own enlarging. For me, film is more “real” and honest than digital

    • Short answer: no. I spend enough time doing it that a) I just use my Macbook pro screen plus the apple calibration utility; b) my prints turn out exactly the way I want them to and c) I trust the latter to a master printer. But he agrees that the files look pretty darn good. Is this the most accurate way? No, but then again, even if you are using the most accurate method available, you need to have the eyes/ experience/ memory to know how the original reality looked and be able to match it. I have a student who’s color blind but yet manages to produce the most stunning landscape images – and the color looks just fine to me.

  10. Thanks for this detailed article, Ming. And for that great knowledge base you have been building so far.
    This subject is somehow mysterious to me.
    One question: I have been using sRGB, can I switch to ARGB just like that? No strings attached? Will I see a difference on a MBP 13″? Or “just” others with a good display?
    Well, that were 4 questions ;-) cheers, Frank

  11. An excellant article, very clear and understandable!

  12. Ming, I was wondering if this workflow would make a difference : I use Capture One raw converter, so I could set the to produce 16 bit TIFF from the RAWs , in Prophoto. Edit that in PS and when done, convert to SRGB or AdobeRGB before outputting to JPEGs. Would that make any difference over just leaving the TIFF as sRGB or AdobeRGB (my thinking being that perhaps it’s better to edit a tiff in PS with the largest possible color space). I’m talking about the final product as being for flickr (I know you can even upload prophoto jpegs to flickr, but they look horrible)

  13. Yup, an Adobe JPG would be interesting because it can hold more colors. The question for is, where will it end up. I consider them output only and it needs to match the receiver.
    Usually the only JPG receiver I know that will handle Adobe RGB is print shops.
    The rest of the world is better off with sRGB unfortunately ;-(

    Re Working Space, yes, of course the heavier your manipulations, the more this affects you. But as your blue sky tone or my intensely red flower examples show, there are things close to the gamut border that are affected already in day to day use. So having a wide workflow until the absolute end is just a way to ensure that you do not accidentally clip out things on the away without noticing.

    cheers
    afx

  14. Hmm,
    I think this is a bit cavalier on the camera color space settings for raw files.
    It affects several things:
    1: The histogram displayed on the camera which is based on the embedded JPG in the raw.
    2: The default settings of the camera manufacturers raw converter
    3: On some older Nikons (and I don’t know how many others), it has an influence on the AD conversion (Thom Hogan wrote about this a few years back), but it seems to be barely noticeable.

    So for a slightly more accurate histogram, Adobe RGB would be the sensible choice. But if you occasionally need directly extracted JPGs, sRGB seems to be the more useful.

    And with regards to the working space, using Adobe RGB still has a good chance of clipping at the gamut boundary. ProPhoto is a much safer choice.
    You might want to read the article on my site.

    http://www.afximages.com/articles.php?article=WorkingColorProfile

    Even with a low end toy printer, printing 16bit TIFF images of saturated colors (for example red roses or tulips) and comparing them to the original object, results in more accurate colors when the complete workflow up to the printer profile conversion is based on ProPhoto than with Adobe RGB.

    cheers
    afx

    • You’re right on 1-3, except 2 is not relevant if you use a third party converter; 3 doesn’t really apply to modern cameras. I disagree with sRGB being better for directly extracted JPEGs – the more color gamut, the better.

      ProPhoto is a virtual space; you’re going to have issues with displaying the gamut. Most monitors don’t even cover the majority of ARGB as it is; even fewer browsers etc are color aware. Since the majority of presentation these days is digital – I still think the safest compromise is ARGB…

      Your monitor/ printer calibration is going to matter more than the color space for most. But again, I agree – with the caveat of it depending very much on the printer model used.

      • Well, if someone extracts JPGs directly, it is usually for immediate use, so AdobeRGB tends to be rather risky for this as the typical recipients in those cases often don’t even have a CM aware system.

        With regards to ProPhoto, you are falling into a trap here, what your typical output can display is completely irrelevant for the choice of *working* space. The important part is, that your working space is bigger than your input to allow manipulation without clipping, see the referenced article. Adobe RGB is still tiny compared to what the camera delivers, whereas ProPhoto encompasses it.
        You will always loose something at the end and will never see the full gamut that your camera delivers (both screen and printer will not be able to do this). The question is, do you loose it by clipping because you restrict your working space early or by a controlled conversion to the output gamut at the end, be it screen or printer. What you will see is always an approximation, the question is, how much losses will you have before you arrive at the end.

        cheers
        afx

        • Good point re. the likely user of an OOC jpeg. Still, I find ARGB jpegs tend to help with clipping issues and odd sky shifts especially.

          That explanation makes sense. I imagine it would make more of a difference if you are doing extreme tonal manipulation which results in previously out of gamut colors coming into the viewable output gamut?

  15. I have a query on shooting RAW. They say it shouldn’t matter what your colourspace is if you shoot RAW, as there is no embedded colour profile with it. It only matters to set it to AdobeRGB as opposed to sRGB if you look at your images on screen as it’s showing the JPG embedded in the RAW file and that’s affected by the colourspace. Then again, the LCD on the camera might not even be capable of giving you an accurate output. So does it matter if you set it as AdobeRGB or sRGB in camera?

    • Depends which camera – some do embed the color space info anyway, like the Nikons. And it does make a difference. Some default to Adobe anyway (like the Leicas).

      • As usual Ming, an excellent and very readable article, thank you.
        And very useful to know that Nikons embed color space! I read somewhere else that it doesn’t matter and, as a consequence, I’ve never bothered to change the setting on my D800. I will now!
        Interestingly though, I don’t think I will have had as many problems as I may have at first thought. I use Lightroom and that assumes a wide range colorspace (pro I think) for raw images so I should be ok… unless of course it’s being clever and uses the color space set in the (Nikon) camera (which it does for print definitely).
        A useful page to look at is this one

        http://livedocs.adobe.com/en_US/Lightroom/1.0/help.html?content=WS0F7BFFFA-CE53-4ceb-B3D3-9D6256B8917D.html

  16. Good article! One question: I thought that the color space you set in camera doesn’t matter if you shoot RAW. In-camera color space selection only applies to the back-LCD preview and in-camera JPG conversions, does it not?

  17. hi ming thein, i see MacBook Pro is part of your workflow. I just calibrated my mid 2012 Macbook Pro ( 15 inch matte screen ) with Spyder Elite and i found out MBP`s Adobe RGB coverage is poor . i can say it only covers around 80% of adobe RGB . Even Dell 24 inch U241 give better Adobe RGB coverage . Any comment ?

  18. Thank You! You explain things very well!

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  1. […] the cameras as well as the display media – be it digital or print. Part of this is down to colour space restrictions, and part of this is down to the fact that plants naturally reflect light in the UV […]

  2. [...] your monitor to ensure what you see is what other people see! Work in a large-gamut color space to preserve as much tonal latitude as [...]

  3. [...] 3. an excellent primer on colour management for photographers by Ming Thein [...]

  4. [...] Color spaces, from Wikimedia Commons; reused under a Creative Commons license. Image by Cpesacreta. What is clear here is that none of the common color spaces or reproduction methods can display th…  [...]

  5. [...] Starting from the start, a colour space defines all of the possible tones and hues that a single pixel may take. The values may take either a RGB value or CMYK value; the set of three numbers represents the amount of each colour present from a scale of 0-255, which gives 256 possible tonal values for each colour (red, green, blue or cyan, magenta, yellow and black). Combining every possible permutation of these gives you 16.7 million possible different colours for RGB. Note that you don’t get 4.3 billion colours for CMYK, because the K (black) value controls the overall brightness and density rather than contributing another possible hue to the mix.  [...]

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