Choosing a color space: sRGB, Adobe RGB and ProPhoto RGB

Once you start working with images you will quickly encounter different options for working color spaces. These spaces are responsible for a range of tone and color the image produces. The larger the space the more of a range the image can potentially portray. I am being asked quite frequently “what color space should be used” and “why not just use the biggest”? The answer to this question is not as straightforward as one might hope it would be, and it largely depends on photographer’s preferences, workflow and mode of image distribution.

Color spaces

There are three most common color spaces: sRGB, Adobe RGB and ProPhoto RGB. Each has a different range of tones, brightness and colors it is capable of operating with and each is used for different applications.

sRGB (aka sRGB IEC61966-2.1) – is a color space produced by HP and Microsoft in the late 90s. Since this color space was backed up by industry leading giants it quickly became popular with all image driven mediums such as cameras, monitors, scanners and printers. sRGB has the smallest range of tones and colors (about 35% of the full International Commission on Illumination (CIE) range) out of the three most popular color spaces, but it is the most versatile and widely used. It is supported by all cameras, screens and image viewing software, so if you just want to keep things simple and avoid color shift problems during editing or sharing, your best bet would be to shoot and edit files in this color space.

Adobe RGB (1998) – as you can probably tell by its name, this color space was created by Adobe in late 90s for suitable implementation of full color management in their Photoshop software. Because of wide use of Photoshop this color space quickly became popular and extensively supported. This is a wider color space, which encompasses around 50% of all visible colors (as defined by CIE), it is a good choice for editing in 8-bit or 16-bit modes and typically carries more information for print. However, there are some complications associated with using this color space that you should be aware of.

First of all, Adobe RGB is not supported by all browsers. If you intend to place your images online it is most likely that people viewing your images will see them in slightly different colors if the file is in Adobe RGB color space.

Secondly, Adobe RGB compresses colors and only special image viewing software’s can expand it back to reproduce all the colors in full gamut, all of the rest of the programs do not support this color space and will make the image look dull. So when you share your images, remember to convert them to sRGB. This creates an additional step in your workflow.

Finally, if you send your images to a print lab, most of them work with sRGB color spaces (unless they specifically mention a different color space) which will mean your prints would have incorrect (dull) colors, if printed with Adobe RGB profile.

ProPhoto RGB – was created by Kodak for advanced image reproduction on print. This color space covers the largest range of colors and even goes beyond of what our eyes can see. To achieve this range you must shoot in RAW format and open your digital negative with ProPhoto RGB color space in 16-bit mode. If you start editing in 8-bit mode you will most likely run into banding or posterization problems because with only 256 levels per color channel in 8-bit mode gradient steps are larger. Additionally you will not be able to save the file as JPEG because it only supports 8-bit mode. You will have to store the file in a format that supports 16-bit such as PSD or TIFF, and your printer will have to support this format. Therefore this color space is only recommended for photographers who have a very specific workflow and who print on specific high-end inkjet printers which can take advantage of such a high range of colors.

So which color space should I use?

color-spacesAs I have mentioned before, it all depends on your preferences and character. If you are planning on sharing your photos online, printing them at conventional mini labs or providing them to clients who have no idea what a color space is, then your best choice is sRGB. This is the most versatile color space and the use if it eliminates any hassle of converting and having extra steps in your workflow, giving you more time to actually shoot more images and focus on your creativity. Remember that most color problems occur when you start messing with color spaces other than sRGB

On the other hand, if you are the kind of person who likes to control every aspect of your workflow and print your images at home on advanced inkjet printer, then you should consider using Adobe RGB color profile. Additionally, sometimes specific clients, especially in publishing business, will explicitly ask you to provide images in Adobe RGB color space, because theoretically it has a wider color range. In that case you would want to use Adobe RGB and carefully monitor each of the transfer steps in your workflow.

Finally, if you are a complete perfectionist who prints on high-end inkjet printers and wants to make use of the entire color range visible to human eye and even some imaginary color (yes, there are imaginary colors employed by this color space) then you should go for ProPhoto RGB. This will, however, force you to use very specific steps in your workflow, such as shooting RAW (ProPhoto RGB is native space for Camera RAW) and only using 16-bit files.

Assigning color space in camera

Most modern digital camera support sRGB and Adobe RGB color spaces. You can usually specify which color space you want your camera to use when saving JPEG files on a memory card. To choose it go to menu and look for color space option. Please refer to the user’s manual for your specific camera instruction.

Assigning color space in Camera RAW

If you shoot in RAW, then you can choose a specific color space when opening a file in RAW software. In Camera RAW, which comes standard with Adobe Photoshop, you can do this by clicking on bottom link in the middle of a window and selecting a color space from a Space drop down box. Remember to also select 16bit/Channel depth if you are choosing ProPhoto RGB or even Adobe RGB color space.

Camera Raw Color Space

Setting up Photoshop color setting

When working in Adobe Photoshop also remember to select appropriate color settings. You can do this by going to Edit>Color Setting on the top Navigation Panel. Once there, select RGB working space and make sure to check boxes that will prompt you if there is a profile mismatch to avoid any inconsistencies.

Switching between color spaces

Convert color spaceSometimes you might want to switch between different color spaces. This can be done with several editing programs. Remember that you don’t want to just assign a new color space, but want to convert to it using advanced algorithm in order to correctly preserve all the colors. I will use Adobe Photoshop as an example. To convert color space, go to Edit>Convert to Profile on the top Navigation Panel. New window will show you your current color space and give you an option to select which profile you would like to convert to. This conversion can be done through four different methods (Perceptual, Saturation, Relative Colorimetric, and Absolute Colorimetric). If the description of these methods below seem overwhelming just know that you are better off just using Relative Colorimetric conversion method for your photos.

Perceptual mostly focuses on keeping good correlation between out-of-gamut colors, but it may negatively affect the relationship of in-gamut colors. This is sometimes effective when converting to CMYK color space.

Saturation, as the name implies, is focusing on maintaining good saturation of colors. It is usually used when converting to wider color space. But it is typically not recommended for digital photography, because it doesn’t preserve realistic colors.

Relative Colorimetric focuses on accurately producing in-gamut colors, but it sometimes sacrifices out-of-gamut colors. This is the best rendering option for photos and is most used for screen and print.

Absolut Colorimetric is typically used for proofing. It tries to reproduce all original colors, but does not take into consideration for the illuminant or light source. This usually causes wide color shifts when viewed under different lighting. Therefore, this method is not recommended for photography.

Color Proofing

Additionally you can use color proofing to see how the image might look like on different mediums. Remember, however, you monitor should be properly calibrated to present colors close to real results. To set color proofing in Adobe Photoshop go to View>Proof Setup on the top Navigation Panel and select which ever medium you would want to see it in. Make sure Proof Colors is active at View>Proof Colors to see results.

Final thought

Personally, I use sRGB colors space exclusively for all my projects. This allows me to share, post and sell images without ever thinking about end user seeing noticeable color shifts; unless their monitor colors and gamma are way off by default, but in that case they see all images like that and are probably used to it. I know many of my collogues use Adobe RGB to maintain larger range of gamut but I keep on hearing all kind of stories from them how that gets them into problems. And honestly I can’t see such a quality difference between a print from sRGB and a print from Adobe RGB to justify to myself to go through all the hoops.

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This entry was posted by Alex Gumerov.
 

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  1. So can i shoot raw in RGB , transfer the files on to my PC and get my screen adjusted in RGB for true colour?
    I ask this because the newly purchased Asus P246 does not allow me to colour adjust in the SRGB settings.
    Given the above I would want there for want to work in the RGB range and then convert it when saving to SRGB.
    Is this the correct process in my case? Should I there for not shoot in RGB first also?

    • Thats correct, but since you are shooting RAW in the first place it doesnt matter since RAW format captures all the possible information from which you can then convert to your preferable color space.

  2. Question or maybe a comment regarding color space, you suggest using Relative Colorimetric which is good for the screen or printing. Printing on what kind of printer??

    After converting my photos to sRGB they will be sent to a lab and it’s printer uses CMYK. Therefore, I assume under this scenario Perceptual would be what should be selected?

    • Perceptual is sometimes beneficial for CMYK printing but if you will be sending it to a lab I would use Relative Colorimetric which is a good middle ground. However, I would not recommend converting to sRGB if you are going to print those files. sRGB is mostly beneficial for screens. I would recommend sending a file in Adobe RGB or ProPhoto RGB (if converting from RAW) color profile to a printing lab. In this case, there will be more color retention when the lab converts it to CMYK. Talk to your lab and ask them what works best for them, some printers will even accept .tiff files which do not compress files as .jpg does.

  3. sRGB actually goes back to *video* standards… It should be emphasized that it involves a non-linear transformation from the really raw rgb voltages first generated in the camera. Because the eye sees (and hears) logarithmically (think decibels) it would have been rational to have R=log(r), etc., but that’s not how it works.

    Instead, a power law transformation is applied. Why? Because the phosphors in old cathode ray tube (CRT) TV’s respond as the 2.5 power of the voltage of the electrons smashing into them. So it’s convenient to encode the camera signals as the 1/2.5 (=0.4) power to neatly compensate for this. sRGB actually uses the slightly higher 1/2.4 power for various reasons. This arrangement survives even though TV displays are all solid state now, and so the original rationale for doing this way is no longer there.

    This doesn’t have anything to do with color spaces, but the sRGB primaries are very close to both the old NTSC primaries and the slightly different newer ones upon which HD TV is based. One is rarely aware of out-of-gamut colors when watching TV.

    Maybe big color spaces like ProPhoto are better in principle, but they can increase the number of out-of-gamut colors, and associated problems. Even all of sRGB color space is beyond the gamut of most subtractive (printer) display systems. SWOP-CMYK color space is bigger than sRGB, but not even as big as Adobe RGB.

    • Since we’re getting technical, Adobe RGB was also initially a color standard for some early HD format TV and was A dopted by A dobe. And inkjet printers are CMYK, Cyan, Magenta, Yellow and Black so no big deal there. Besides, if you use ProPhoto color space to edit you will manipulate colors that are out of gamut on a typical monitor and even on wide gamut monitors which means you are editing in the blind for lots of color and no way to tell prior to print so it’s pin the tail on the color donkey when printed. Just my opinion anyways.

  4. hi i have black and white images that are in srgb i want to convert to 8bit gray scale to print in photoshop is this possible Thank YOU Frank

    • Hey Frank, yes its possible. Go to Edit -> Convert to Profile in Photoshop and choose Working Gray in Destination Space. Just make sure your printer accepts this color profile.

  5. Many thanks – this was the best !

    However, my situation is that my Microsoft PC (surface) use Adobe photo express color space RGB.
    Don’t know what my my camera (Canon) use!
    But the print company use sRGB.
    My prints turn out more dull and slightly darker.

    If I understand above I can covert in the Adobe program ….
    But would there not be another photo program that I could download that use color space sRGB?
    Thank you so much from Kirsten – KY

    • Hey Kristen,

      I am sure such programs exist but I am not aware of any of them. However, all Canon cameras I’ve used have an option to set Adobe or sRGB as color space. If you shoot JPG only and your print company wants sRGB, then set your in camera color as sRGB. Or shoot in RAW and open in any color space you need 🙂

      Best,
      Sergey

  6. Hi admin, nice tutorial. you explained everything in detail. Now all of my doubts are clear. I’m going to use sRGB color profile for online applications (images for website and social media sharing). I have one question. Will the size of image having color profile of Adobe RGB will be greater than sRGB IEC image?

    • Hey Safalta,

      Adobe RBG is a larger color profile so it will have some more information but as far the the file size, the size difference will typically be too small to have any significance.