Windows 7, monitors and sRGB

[angie_nelson]

<p>I have two possible monitor profiles. One the basic sRGB,and the other from the Spyder 2's calibration (I was surprised it still worked but it does). I'm honestly overwhelmed about what to choose here because you have one group of people saying sRGB everywhere, and another wanting the widest gamut possible on the screen so that you can see what you're doing for printing. </p>

<p>My intention is to do quite a bit of printing and scanning at home. I used to use AdobeRGB for everything, but some devices don't list it as an option, and I'm not sure if it's too kludgey to add it or not. So I'm attaching the screen I'm looking at in the OS. Though, it's not clear if the sRGB space "lives" in the monitor, the video card or the OS. Seems like I'd need three places to check to really get this right. Anyone using Windows? What do you do?</p><div></div>

[Wouter Willemse]

<p>Use the calibrated profile for your monitor. The "use sRGB anywhere" (similarly use AdobeRGB anywhere) mantra applies to the colour profile assigned to the image. For the devices used to display the image (monitor/printer), always use their calibrated profiles.<br>

The point is *not* using the same profile for all devices, but to ensure all devices are calibrated, so that they are capable to accurately display the values of the image according to the colour profile embedded in the image. If you're mainly going to print, using AdobeRGB for the image, in combination with good colour profiles for your printer with the paper you use, is a sound choice. If you're going to share images on the web, sRGB is a better choice because it is the lowest common denominator, and hence the most likely to display correctly on most screens (calibrated or not).<br /> But this does not mean the screen and printer need those profiles - they need their own to transform "AdobeRGB data" or "sRGB data" in the right representation.</p>

<p>Do note that you need to redo your monitor calibration on a somewhat regular interval to ensure it remains accurate.</p>

[ant_nio_marques]

<p>First: forget everything. Now: read below.</p>

<p>When you use a profile for a device, what you're doing is telling the computer how that device shows colours. So, ideally, you should use a calibrated profile, that is, an actual measurement done by you or a technician, of how your specific device behaves.</p>

<p>When you use a profile for an image, what you're doing is tell the computer how it should interpret the colour values in the image. And here is where those names (sRGB, AdobeRGB, etc), come in. Those are standard ways of converting values into colours, and they have varying strengths and weaknesses. sRGB is rather limited in the colours it can encode, but it was designed to match what most monitors of the time could show. So, sRGB is weak and will round off a lot of your colours (if you happen to have colours to round off, of course), but it has the advantage that almost anything on Earth is able to show it correctly (that is, colour distinctions that sRGB doesn't allow will be lost, but those that it does allow will be shown correctly). AdobeRGB is much better but not perfect, and less compatible. ProPhotoRGB is even better, and even less compatible. So, it all boils down to what devices you will be using your images with. And software - lesser programs may always assume an image is sRGB even when it isn't, and so the colours will be off. What you can never do is simply to say the image is in a given profile when in fact it isn't. Your picture is such an example - one or both of them are wrong. You can convert images from one profile to another, but that involves the program actually shifting the numerical values of the colours in the file so that they are the correct ones for the new profile. By contrast you can't actually change the profile of a device: the device produces or renders colours in a given way, and there's little yoiu can do about it.</p>

<p>Device profiles and image profiles aren't alternatives, you need both. A correct image profile to tell the computer what the colours actually aren and an accurate device profile so the computer knows how to make the device show the correct colours (printer or monitor) or what the device-provided colours are (scanner).</p>

<p>When scanning, the scanning software will produce an image in a given profile, say, the scanner's profile, or one you provide yourself, or a standard such as sRGB or AdobeRGB. According to the profile you choose, the numerical values of the colours written into the image will be different, but in all cases the colours will be correct (unless you provide the scanner's profile yourself, and provide a wrong one). The difference will be in the colour distinctions that may be lost. A user-provided calibrated profile will be the best, since it will match the source data best (it may be not as powerful as, say, AdobeRGB in some regard, but that doesn't matter, because that means the specific extra power it doesn't have isn't used anyway). When sending files out to print, you should use AdobeRGB, because that's what every respectable lab should be able to handle now. When producing images for the web, sRGB is a safer bet (people's monitors won't be able to show the difference anyway). What you don't want is to send an AdobeRGB file to someone who will treater it as it were sRGB, because the colours will be wrong.</p>

<p>If you like the look of using the wrong profile, that's another matter, of course!</p>

[angie_nelson]

<p>Thank you both for your insights. If I understand correctly, then in the example I gave above, the dialog box is asking me something like this:</p>

<p><br /> "If you give your monitor sRGB or AdobeRGB (or any other) input, then your monitor behaves most correctly (color correctly) when it interprets the data according to which of these:</p>

<p><br /> calibration(spyder) or<br /> sRGB (with basic Windows calibration) ?"</p>

<p><br /> OK, if that's what that dialog is saying then I know what to choose. Correct me if I'm still misinterpreting it.</p>

[digitaldog]

<p>In ICC aware (color managed) applications, the system looks at the embedded profile of your documents to understand the scale of the numbers. Then it looks at your display profile and produces a unique compensation for a proper (if properly calibrated) preview. This is called Display Using Monitor Compensation. If you are working in applications that are color managed, you always want to use the custom display profile, not any generic profile or the numbers in the document isn't previewed correctly. In such applications, the display is divorced from how you edit the numbers such you can use any RGB or CMYK data with an embedded profile and those numbers are correctly being previewed. </p>

[angie_nelson]

<p>Andrew, I have a couple of questions about what you said...<br>

What exactly is "scale of the numbers"? I'm finding that hard to understand. If I have a tri-numeric RGB, then what does scale have to do with it? Is scale the same thing as luminance or how much opacity the color has when you pass light through it on a screen?</p>

<p>I'm not sure I follow what you said here.. "in (color managed) applications, the display is divorced from how you edit the numbers.." Are you saying that the numbers in the file (myphotoname.jpg) never change during editing? I assume not. </p>

<p> </p>

[digitaldog]

<blockquote>

<p>What exactly is "scale of the numbers"?</p>

</blockquote>

<p>Analogy. You can talk about 1 foot or 1 yard. Both use the number 1 right? Different scale. <br>

0/255/0 is the same number but the scale and thus color are different in sRGB vs. Adobe RGB (1998). The color space defines the scale. </p>

<blockquote>

<p>in (color managed) applications, the display is divorced from how you edit the numbers.."<br /></p>

</blockquote>

<p>Prior to Photoshop 5 and ICC color management there, all the numbers were sent directly to the display. In Photoshop 5, Adobe introduced RGB working spaces. They are divorced from the display. The numbers are based on the scale of those color spaces. They interact with the display profile and with Display Using Monitor Compensation, you get your preview. That's nothing like non ICC (color managed) applications which send the numbers to the display. They have no idea if 0/255/0 is sRGB or ProPhoto RGB or EpsonLuster RGB. It's just a number. Numbers alone don't tell us what a color looks like. </p>

[angie_nelson]

<p>That's very clear, thanks, Andrew!</p>

[ant_nio_marques]

<p>@Angie, the above dialog is merely for you to tell Windows how your monitor renders colours. It doesn't really matter what format the image files are (sRGB, AdobeRGB, etc), what you are choosing there is how your monitor will show whatever colours Windows feeds into it. If one of those is its correct profile, then by choosing it the monitor will show what Windows thinks it will show. On the contrary, if it's incorrect, then Windows will think it is showing colour A when in fact it is showing colour B.</p>

<p>But we can't tell you which one to choose because from their names they both seem to be custom-made profiles. If both were correctly made using good tools, then they should be more or less equivalent. Sometimes, there are profiles available on the Internet for given monitor models; those are not made by measuring your own monitor, which would be the only foolproof way, but by having some confidence that monitors of a given model will always behave very close to a certain standard. But neither of your options seems to be such a generic profile, they both look like something someone made. Now, whether they were made for your monitor or not, is something that only the person who made them can tell.</p>

<p>As to sRGB/AdobeRGB/etc, those are profiles that you find in an image file, describing how the numerical values in the file should be interpreted. They have nothing to do with your monitor, aside form the (for now irrelevant) fact that your monitor may have been designed to have a gamut close to one of those standards. (A monitor which is only capable of showing the colours that can be expressed via sRGB will show a correctly-identified AdobeRGB image as if that image had first been made to fit within sRGB: correct colours, but with loss of distinction).</p>

[angie_nelson]

<p>Thanks, António! Yes they're both calibrations, the one with a date is made by Spyder and the one that starts with sRGB was made by the Windows 7 built in calibration.</p>

<p>Looks like I get better results with the Spyder, but it's a bit too warm. Small price to pay. I can do it again sometime when my arm recovers from holding it up. </p>

<p>Where would I look for a specific monitor profile? The Asus website maybe? </p>

<p> </p>

[ant_nio_marques]

<p>Angie, from your reply I'd say you've gotten the concepts correct.<br>

Your profiling with the Spyder must of course be done using the same settings on the monitor that you will be using afterwards.<br>

For generic profiles, I'd google for the monitor model plus "icc". But there's no guarantee the results would be better than what you have.</p>

[steven_clark]

<p>It's worth mentioning that monitor profiles in particular also store a LUT (lookup table) that gets loaded into the graphics card which is used to calibrate the brightness response of the screen (but not gamut) closer to something like sRGB so that for non color-managed applications you're at least showing colors with the right contrast if not the right coloration.</p>

<p>Usually these profiles are created yourself with the Spyder or another sensor, factory profiles are often not as good because your colors are slightly different from theirs. Some of what I just said may not be quite as true as it was when monitors used phosphors excited by electron beam.</p>