Why Use the ProPhoto RGB Color Space? (Podcast 423)

Why Use ProPhoto RGB?

27 May Why Use the ProPhoto RGB Color Space? (Podcast 423)

I’m often asked which color space to use in Photoshop, and when I tell people that it’s best to work in ProPhoto RGB, I hear various reasons why people don’t think it’s necessary. One of the main ones is the camera’s widest color space is Adobe RGB, but that of course is not true. Adobe RGB is available as a better alternative to sRGB for use in the JPEG previews in your RAW files, or if you should for some reason shoot in JPEG, that’s your lot.

Once you have your images in Lightroom though, it automatically uses ProPhoto RGB, you can’t even change it! When you go over to PhotoShop though, you have a choice, and far too many people select Adobe RGB or even sRGB, because that’s what your images are often exported in. Today I’m going to show you why that’s a mistake.

If you are already up on color spaces and just want to get blown away, skip down to the video below. If this is all going over your head a little, read on first…

What is a Color Space Anyway!?

Spectrum Locus with sRGB and AdobeRGB Color Spaces

Spectrum Locus with sRGB and AdobeRGB Color Spaces

Just in case you don’t know what I color space is, briefly, in this diagram you can see the Spectrum Locus, which represents all the colors that we can see. Computers work with large amounts of data much better though, if that data can be mapped out mathematically, so over the decades a number of clever people have created what are called color spaces, that basically map out colors based on straight lines forming a triangle within the Spectrum Locus. This enables us to give each color a number, that can be used to create that color on a computer.

As we see here, sRGB is actually quite a small segment of the visible spectrum, and although better, Adobe RGB is only in reality a bit larger that sRGB. To really show you the relationships between these color spaces and a bunch of others, in the video below I use a tool called ColorThink Pro to make it plainly obvious that ProPhoto RGB is the way to go when editing your images in Photoshop or any other image editing software.

ProPhoto RGB in PhotoShop

Photoshop Color Settings Dialog

Photoshop Color Settings Dialog

To set ProPhoto RGB as your working color space in Photoshop, just go to the Edit menu, and select Color Settings, and you’ll see this dialog box. Just select ProPhoto RGB as the RGB working space. Don’t worry about CMYK for now. You will usually only use that in pre-press work and when necessary, you’ll be told what color space to use.

I also turn on Ask When Opening and Ask When Pasting for Profile Mismatches and Missing Profiles too. This prevents me from using the wrong profile without realizing it. Really though, once you’ve made this change, you can pretty much forget that you are working in ProPhoto RGB, and just reap the benefits.

(Click on the screenshot to view larger.)

This goes for any other image editing software too of course. Whenever you can select ProPhoto RGB, it’s always best to do so, and save your working files in this color space, then use sRGB when exporing for Web or Adobe RGB when necessary, sometimes for printing services, and some stock sites prefer Adobe RGB, but that should only be selected when exporting your images for these purposes.

Editing in ProPhoto RGB from Lightroom

Lightroom Edit Image Dialog

Lightroom Edit Image Dialog

Note that if you send files from Lightroom 5 to Photoshop, there is no need to specify a color space as you leave Lightroom. When you do round-trip editing in other plugins though, such as Silver Efex Pro you will need to specify ProPhoto RGB as your color space, as you see in this screenshot (right).

As an aside, always select 16bit in the Bit Depth pulldown too. As a rule of thumb, to ensure that you never shoehorn your images into a smaller workspace, select the highest possible setting, unless it imposes unrealistic limitations on your workflow.

Some other plugins and applications, such as onOne software have their own color space setting. Surprisingly, onOne software is installed with Adobe RGB as the default, so you need to change this to ProPhoto RGB in the preferences before you start using the program. Once set though, it stays set, so the time investment in using ProPhoto RGB is minimal.

Not Throwing Color Away

It is worth noting of course, that you aren’t exactly throwing away color when you export to these smaller color spaces. The conversion takes into account the difference between the color spaces, and compresses and remaps the colors to fit into the smaller color space. You usually can’t see a difference on a computer display.

Wiggle Room and Future-Proofing

The major benefit of working in ProPhoto RGB is to maintain your full data for editing wiggle room, and printing, and we will also probably see wider and wider color spaces available in displays in the future too. Please don’t limit your images to today’s technology.

See for yourself!

Anyway, take a look at the video. I was giggling like a schoolgirl when I first looked at ProPhoto RGB in ColorThink Pro, and I hope this helps you to understand why working in ProPhoto RGB is really the only way to go. Don’t forget to go full-screen!


 Pixels 2 Pigment Aug 2014

Before you go, I just wanted to let you know that having just finished the first In-Studio Pixels 2 Pigment workshop, we’ve set the dates for the next one! It will be held on Aug 23-24, 2014, right here in my Tokyo studio. For details take a look at the Pixels 2 Pigment page. I hope to see you there!

P2P In-Studio


Show Notes

ColorThink Pro: http://www.chromix.com/colorthink/pro/


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  • angelo bufalino
    Posted at 02:29h, 09 January Reply


    Excellent video and explanation. Seeing that you are certainly on top of your color space knowledge, any tips for avoiding banding in images during the workflow and export? I am referring to a shot say at night, captured in RAW, that starts to show banding in the sky. Thanks in advance!

  • William Walker
    Posted at 17:46h, 08 June Reply

    Hi Martin

    A great video! Thank you.

    I am in the process of setting up a commercial print studio and would love to link this video to the website that I am busy building. Would that be ok?

    William Walker

    • Martin Bailey
      Posted at 17:51h, 08 June Reply

      Hi William,

      Sure, no problem. Just please ensure that you grab the embed code from Vimeo, so that the video is played in its entirety. If you have any problems, please drop me a line and I’ll give you a hand.


  • squawking7000
    Posted at 16:09h, 01 June Reply

    One thing that should be remembered that Pro Photo RGB is not supported by all web applications. I changed the Export colour space in Lightroom from sRGB to Prophoto and the final version that went to one web site was really drab looking, while the same picture uploaded to Facebook and Flickr still retained the original vibrant colours. Curious.
    Very interesting Podcast Martin on a very technical subject

    • Martin Bailey
      Posted at 17:52h, 01 June Reply

      Absolutely. I mention in the video and post too that you should specify sRGB for web. Some browsers understand different color spaces, but you can’t be sure that people will be using these browsers so at this point in time, sRGB is recommended for web.

  • Steven James MartinS
    Posted at 01:16h, 30 May Reply

    A very interesting video, but do you ever actually see all of this extra ProPhoto RGB data?

    It seems as though the screen range (and even more so the print range) of colours is smaller, so I don’t see the point … maybe I’m missing something.

    • Martin Bailey
      Posted at 09:21h, 30 May Reply

      Steven, as you saw, the reds in my photo were already outside of the Adobe RGB range. The camera captures more data than the Adobe RGB range. By using Adobe RGB you are compressing the data that your camera creates from the word go. That should be enough to use ProPhoto RGB, no? Just because you don’t use the full range, doesn’t mean that you should compromise your images by shoehorning them into a smaller color space, even if the computer displays are not displaying the full range.

      At the very least, in a few years time, when displays actually show much more information, people that processed in sRGB or Adobe RGB will look at their images created now and cringe. They’ll be full of crunchy gradations and patchy color, and you wouldn’t know until the display catches up. Have you ever taken a look at an old 8bit 256 color graphic made in the 90’s on a modern display? Not nice. :)

  • James A.
    Posted at 06:50h, 28 May Reply

    You mention that you can’t change the color profile used in Lightroom. I’m not on my PC at the moment but can’t you change the color space for the develop module in Lightroom in the soft proofing panel?

    • Martin Bailey
      Posted at 08:55h, 28 May Reply

      Hi James,

      Yes, you can change the profile for softproofing, but it’s only emulating what the image will look like when using that profile, typically for printing. It isn’t actually changing the profile that is used to display and work with the images. There is no way to do that, and for good reason. Lightroom wouldn’t be able to do the amazing things that it does if it were restricted to a smaller color space.


      • James A.
        Posted at 08:24h, 01 June Reply

        That wasn’t my understanding of how it worked. Changing that setting changed what it actually uses in develop mode and I think that was direct from Adobe.

        • Martin Bailey
          Posted at 13:15h, 01 June Reply

          No James, that’s not how it works. The profile is only used for soft-proofing. You can save the image or create a virtual copy that saves the changes made while soft-proofing, but as soon as you turn soft-proofing off, the base image is displayed again using ProPhoto RGB. If you show me what you saw on Adobe I’ll try to explain why it’s confusing you.

  • Murray Foote
    Posted at 01:55h, 28 May Reply

    Hello Martin

    A very interesting video. One thing that might be worth mentioning is that if you use Lightroom and launch from there to Photoshop you don’t have to worry because your image stays in ProPhoto.

    I toyed with the idea of purchasing ColorThink Pro but thought I wouldn’t use it enough to justify purchase. Do you use it to assess the gamut of individual images when printing if you suspect they may be out of printer gamut?


    • Martin Bailey
      Posted at 08:58h, 28 May Reply

      Hi Murray,

      That’s a good point, but I’ll expand on our recommendation, because sometimes you do need to specify the color space when editing from Lightroom when a copy is going to be made, such as a PSD or TIFF. I’ll probably add a screenshot of that, just to be more thorough.

      I have only had ColorThink Pro a short time, though I will look at some images before printing. That red flower shot is particularly difficult to print, which is why I chose it to take a look at in the video.


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