Color Working Spaces: ProPhoto RGB vs. Adobe RGB (1998)

A student asks:

Q: What is the best color space to use with Lightroom and CS4?  ProPhoto RBG or AdobeRGB(1998)

A: Best for What?

This is one of those “what’s the best car” questions… the answer can be “Ferrari” or “used Chevy” depending on the intended use. The answer, therefore, depends a lot on what you’re doing with the images… what happens to them at “output.”

It basically has to do with “Gamut” or… the amount of color a given working space can hold, and how the gamut of the working space coincides with the gamut of the printer that’s being used.

ProPhoto RBG is a *very* large-gamut color space. It can hold (or “display” or “show”) a lot of colors; more than Adobe RGB (1998).
Adobe RGB (1998) is a relatively large-gamut color space. It can hold a fairly large number of colors; fewer than ProPhoto RGB.

When you compare the gamuts of these two color spaces to the gamut of a printer/paper combination, you’ll find two interesting things:

  1. ProPhoto RGB holds LOTS more colors than the printer can print, but every color that it holds is a color that we can print.
  2. Adobe RGB holds *most* of the colors that the printer can print, but it does not hold every color that the printer can print.

In other words, ProPhoto RGB displays a huge number of colors that the printer can’t print but, as long as you’re using the “soft proofing” (getting a preview of colors that will be printed on screen) mechanism built into Photoshop (using the “View> Proof Setup…” menu item), then you’re fine. Note that soft proofing is NOT available in Lightroom (not even in the Lightroom 3 beta). In order to get a soft proof, you have to open the image in Photoshop.

So, as long as you use “soft proofing,” it’s OK to use ProPhoto RBG. If you don’t, you’re likely to be *very* disappointed with the colors you can see on your monitor, but can’t print.

If you usually don’t use “soft proofing,” then it may be better to use Adobe RGB (1998), as it displays fewer colors you can’t print (but also displays some colors that you can see but the printer can’t print).

Below are some graphics that show the gamuts of the two working spaces superimposed on the gamut of an inkjet printer (an Epson 4800 with Premium Lustre paper). The working space gamuts (Adobe and ProPhoto) are shown in gray wireframe and the printer space is shown in color. You can see how there are some of the printer colors that “stick out” of the Adobe RGB (1998) space and how ProPhoto RGB envelopes the whole printer space.

Adobe RGB (gray shape) against Epson 4800 with Lustre Paper (color shape)

ProPhoto RGB (gray shape) against Epson 4800 with Lustre Paper (color shape)

**Apple’s Aperture offers soft proofing for output, so you’re not forced to go to Photoshop to get your soft proof.


8 Responses to Color Working Spaces: ProPhoto RGB vs. Adobe RGB (1998)

  1. Nick says:

    Okay, I don’t mean to speak heresy, but I was just watching a video by a photographer (Will Crocket) advocating using sRGB as your editing color space. I believe that the line of thinking was that unless you have a (relatively) advanced monitor that can cover most of the Adobe RGB color space, the compression to you monitors color space for viewing (even when soft proofing) will generate colors that are really what you expect.

    I can say that while I might be able to wrap my head around the “uncompressed-compressed-uncompressed” possibility of mismatch, I don’t actually understand the transforms from one color space to the next, nor the soft proofing “compression” from a large gamut to my monitor’s relatively small gamut.

    Any thoughts on this?

    • Jeff Curto says:

      sRGB against Epson 4800 Lustre paper

      Everyone’s going to look at this a different way, I suppose, but… here’s the problem:
      Inkjet printers have a fairly high gamut of color response. The sRGB working space has quite a small gamut. If you look at the image I’ve posted here, you can see that there are a TON of colors the inkjet printer can print that the sRGB working space can’t display. I suppose if you have a $100 monitor from BestBuy, it’s likely that your monitor will clip a lot of any of the working spaces… except sRGB. But, I doubt that a lot of people (read: photographers and photo students) reading this will have cheap-o monitors; the presumption is that most of us have good monitors that are well-calibrated and profiled.

      Using the sRGB working space is great if your output is something like a Costco printer that uses traditional C-print photographic technology, as these have a smaller gamut than an inkjet printer. But.. if you’re going to an inkjet printer, you might as well see most of the colors you can print.

      A sort of “unwritten” part of the answer I gave to the student’s question above is that the mismatch between printers and color working spaces is a big part of the problem of making prints match the monitor. It’s never easy and it has as much to do with the general mismatch between RGB and CMYK color models as it does anything else.

      For a bunch more about color management, see my “Big Giant Color Management Handout” (PDF).

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  3. coffir says:

    Just learning about this now. Tried to print a photo album on My Publisher and everything printed dark with a green tint. Turns out they can not print prophoto RGB. Any advise as to which printers have this capability?

    • Jeff Curto says:

      Well, the whole point of all of this is that there really are *no* printers that can print the RGB space of ProPhoto RGB. The CMYK printer space is a smaller gamut than the wide-gamut ProPhoto RGB.

      However, your “dark and green” probably has more to do with how you sent the images to MyPublisher than anything else. With any of the “print on demand” (POD) services, you’re usually best off converting your images to sRGB first, then putting them into the POD software.

  4. Darren B says:

    You have to really be careful with using ProPhotoRGB. First of all, your monitor probably can’t display all the colours the printer is capable of printing. In addition to this ProPhotoRGB may include colours that neither the monitor OR printer can handle so you end up with banding.

    Another disadvantage of ProphotoRGB editing, if you edit for digital display then use these images in a slideshow, the colours are completely washed out because most slideshow software use sRGB only. All of the ProPhotoRGB images show as “uncalibrated” colour space.

    The real practical issue is if your monitor can’t display the colours, how do you know what is going to come out of your printer? Simple answer is you don’t unless you do all your editing in sRGB only with a properly calibrated monitor and printer. This is the only practical way of getting consistent results. The expanded colour spaces of AdobeRGB and ProPhotoRGB are purely theoretical and non-practical unless you have a monitor costing many $1000’s that is.

    So bottom line, for practical consistancy with editing and printing, stick to the industry standard, sRGB.

    • Jeff Curto says:

      Don’t know that I completely agree with the idea that sRGB is the best working space to stick with, especially with inkjet printers. With contemporary photo-quality inkjet printers, using sRGB means that there are a number of colors that you won’t be able to see but that your printer can print. In other words, the printer’s output space is more capable than sRGB is. For output to commercial service providers, or for any output device where “maximum” color isn’t all that necessary, sRGB is a good recommendation, but if you want to be able to see all the color the printer can print, using Adobe RGB 1998 or ProPhoto RGB and then using the software’s soft-proofing abilities is a better idea.

      For onscreen presentation of images (slideshows, web, etc) then sRGB is the way to go because the capability of the “output device” (multiple projectors and screens) is variable so a low-gamut space is more predictable.

  5. David says:

    Sorry for coming late to the table, but I’m wondering about BW digital printing. I’ve been thinking that the grays are probably more limited
    by the bit depth (65,536 shades of gray for 16-bit vs. 256 shades for 8-bit.) than by whether or not you’re working in ProPhotoRGB or AdobeRGB, but that’s just a guess on my part. Does anyone know if one is really better than the other, specifically for BW?

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