Color Management: Monitor Profiling
How can you tell if the image you are looking at on your computer actually looks the way you think it does? That may sound like an odd question, but if your monitor is not correctly set up you may be in for a surprise. You've undoubtedly heard the expression "looking at the world through rose colored glasses." Imagine for a minute that everything around you was actually greener than it was supposed to be. When you look at things through your rose colored glasses you wouldn't see the green tint. In fact, everything would look relatively normal since the glasses would compensate for the green.
Now suppose your monitor where those rose colored glasses. If you adjust an image on your computer until it looks perfect, it could actually be too green and you wouldn't know it. The errors in how your monitor is calibrated would compensate for and thereby mask the errors in the file's colors.
Suppose that your printer also is a bit off and that it too prints things out with a rose color cast. It too would mask the color problems of your file. You may have even tweaked the color sliders in the print driver to get the images to print like your screen looks without having any way to realize that you were merely introducing the same problem in your printer settings that your monitor was already inflicting on your display.
If you have managed to make your monitor and printer match when neither one is actually correct, you might wonder if you really have a problem. So long as you never share your files with anyone else, this sort of "closed loop" workflow might actually work, but everyone I know sooner or later wants to at least email an image to their friends. Unless their monitor had exactly the same problem as yours, the colors would look wrong. Chances are, it would have a different color cast and so they would be equally to blame for the how things looked. Even if their monitor were perfect though, it would still look wrong since you sent them a file with a color cast you couldn't see yourself.
So, what's the answer to this mess? Before you can get the colors actually correct in your printer or any other aspect of your system you have to start with profiling your monitor. Only then will you know that what you see really looks the way you think it does.
Due mostly to the spread of digital photography, there are a number of profiling packages available these days. I have and can definitely recommend Monaco Optix made by Monaco Systems (recently bought by X-Rite). Several other companies also make excellent products though including ColorVision and Gretag Macbeth. You pretty much can't go wrong with any of these and with the fast pace of new releases from all three I'm not going to even begin comparing them here — no sooner would I do so than one of them would come out with a new release and force me to revise this. Luckily, they all work pretty much the same way so I'm just going to go forward assuming you have one of them. They're not that cheap I'm afraid, but they have come down in price remarkably over the past few years, and at the same time their quality has continued to improve. Still, it's money well spent since it means an end to the frustration of struggling to get the colors right.
Calibrating and profiling involves adjusting luminance (brightness and contrast) of monitor white and black (the white point and black point), the color temperature of monitor white and the color response characteristics including the gamma curve for each color channel (red, green, and blue). All this information then goes into the resulting display profile to enable the Color Management System on your computer to properly compensate for the peculiarities of how your monitor responds to color. You may be familiar with Adobe Gamma that comes with Photoshop. While this is certainly better than nothing, it is not really an adequate monitor profiling solution. It only deals with gamma and not luminance or color temperature and also relies on you to visually determine what is right. A true profiling solution such as Monaco comes with a small device called a colorimeter that sticks to your monitor to tell the accompanying software what color your monitor is really producing so you get a much higher degree of accuracy. The human eye adapts far too easily to color temperature in particular to be able to do this reliably on its own.
The first thing you need to do is to turn your monitor on and let it warm up for a good hour or so to be sure its color response has stabilized.
After starting up the profiling software, the colorimeter (also commonly referred to as a "spyder" or "puck") is then stuck to the monitor face where indicated and its cable plugged into a USB port. The software will then guide you through the steps for adjusting the brightness and contrast on your monitor along with its color temperature. It will then go through a series of color patches to develop the gamma curves. As your computer and video card attempt to produce each reference color, the spyder will sense the color actually being produced so it can calculate what needs to be done to get it to make the right color. This probably sounds more complicated than it actually is — your part simply consists of doing a few things with the monitor controls when prompted and clicking "Next" periodically.
When finished, the profiling software will automatically install the new profile as your monitor default. It will also add a gamma loader to your Startup group. If you have previously used Adobe Gamma, be sure that the icon for it is no longer being loaded when your system boots. You don't need both.
Since your monitor will now be adjusted to an external standard, the colors you now see will be correct. No more rose colored glasses.
Next week, it's time to start printing.
Update 6/11/2005 - With new inexpensive options such as the Pantone Huey ($89 list price) there's really no excuse not to profile your monitor. At least I can't think of any....