| Are you getting images that are way too dark and saturated when opening images in Photoshop from Stock Photo CDs or from scans that have no embedded profile attached? Chances are you are experiencing a Gamma Mismatch resulting from an improper choice of color management options when opening the file. When opening images that have no embedded profile it's very easy just to click away and open the file in a non color managed way. This is a very easy mistake to make and can result in images that can be very difficult to color correct in the future. This is especially true of images that have skin tones. After working in a production environment for many years I have seen too many images that exhibit this problem. Usually it's photos of where people's skin tones look like boiled lobsters! Once the image has been opened in Photoshop in RGB and then converted to CMYK and then saved, it is usually too late to save the image even with large color corrections. The best way to solve this problem is at the time the image is first opened in Photoshop. In order to accurately judge how the images look for this exercise it is important that you have your Monitor calibrated to a Gamma of 1.8. |
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To begin start with make sure your Color Settings in Photoshop look something like the ones below. The main thing is to have your RGB Working Space in either Adobe RGB or sRGB. Notice in the 2nd dialogue from Photoshop 5.5 that the Gamma of the Working Space is 2.2. This is the very key to our problem and to it's solution. |
| Next begin by opening a file that has no embedded profile. You should be met with the dialogue below if you are using Photoshop 6. For this example the file will be opened as is (non color managed). |
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| Close the image and re-open it again. We are met with the Missing Profile dialogue. This time we will stop and make some important decisions about opening this file. In a color managed workflow we are always working with sources and destinations. Scanned RGB images that contain a scanner profile will be opened and converted into an RGB Working Space profile. From the Working Space we can convert to a CMYK space or output directly using a Printer Profile. However when we encounter a file that contains no embedded profile a wrench is thrown into the works so to speak. Without a profile it can be hard to figure out where this image came from. This is where I like Photoshop 5.5's way of dealing with a mismatch. What we need to do is make an assumption of where this file came from. Where we do it is in the Missing Profile dialgue. Since this photo of the kids came from an older stock photo cd we know a few things. Primarily this image was probably intended for prepress output. Secondly it was most likely edited on a Macintosh with a monitor calibrated to a gamma of 1.8 maybe even on a Radius Pressview monitor. So we can now make an assumpion about this file and act accodingly. We can now assign this file a profile of ColorMatch RGB (which is pretty much the spec of a Radius Pressview monitor) and also most importantly convert it to our working space. |
| Now we have the image that has been converted from a source profile to a destination profile, in this case Adobe RGB 1998. The resulting image looks much more balanced color and density wise and the saturation looks good as well. From here we could now convert to CMYK with confidence. So what we had here was a case of taking an image that was edited in a Gamma of 1.8 and converted it to our Working Space that has a Gamma of 2.2. If you open an image and decide not to color manage (as we did initially) you will get a Gamma Mismatch between working spaces and the opened image will look dark and overly saturated. This example is just one scenario that you might encounter with images that contain no embedded profile. This is why it is always best to save your files with profiles embedded. |
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