1、 Multiple Monitor Matching with Spyder2PRO One of our most frequently asked questions is how to match multiple monitors. There are several types of monitor matching. The most basic distinction is between RELATIVE monitor matching and ABSOLUTE monitor matching. Relative matching usually means to cali
2、brate two monitors to the same standard, for similar lighting conditions, but in more extreme cases can involve intentionally calibrating to different standards, due to different ambient lighting. An example of this would be to calibrate the CRT monitors used for image editing in the nearly dark pre
3、press room to a whitepoint of 5000k, and a white luminance of 85 candelas per meter squared, which are appropriate settings for these conditions; but to then calibrate the editors LCD monitor, which is in a sunny corner office, to a whitepoint of 6500, and a white luminance of 175 candelas per meter
4、 squared. This would not make the monitors match in a literal sense; instead it would allow them to offer the most similar possible results under the different conditions involved. More typically, monitors that are not sitting side by side, but that are under similar lighting levels are simply calib
5、rated to the same gamma and whitepoint values. Each retains its native black luminance, and is set to a matching white luminance, that is appropriate to the ambient lighting. Absolute monitor matching is used when monitors are placed side by side, either on the same computer or on different systems,
6、 but with the intent of achieving the closest possible match between them. In this case it is important that the monitors are of a similar type (LCD or CRT) and for LCD monitors, that they be of a similar quality as well. It is not always possible to achieve tight matches between a low cost general
7、use monitor of one screen technology, and a more expensive graphics or a different type. Also, not all LCDs have similar brightness capacities, or dynamic ranges, so there can be difficulties there as well. And finally, some LCD monitors have larger or smaller color gamuts, or different abilities in
8、 the red, green, or blue zones, so may not display bright colors similarly. Calibration and profiling can improve all of these issues, but cant necessarily eliminate them. Another important factor is multiple monitor calibration on the same computer under Windows. Unless users are running multiple v
9、ideocards, or a PCI Express dual head card, in many cases Windows cannot provide full color management. Vista offers some improvements in this, but often requires upgraded videocards as well. Finally, once you have matchable monitors, and a video configuration that can calibrate and profile them, yo
10、u need to define a target for both (or all) of them. This means checking the current native black and white luminance values for each monitor using Spyder2PROs Tools Info menu item. Compare all black luminance values, and determine the highest black luminance value; this will be the new target value
11、 for black on all your monitors. Please note that this will mean making black on all monitors as weak as your weakest black. Next compare all the native white luminance values. This will tell you how bright each monitor is capable of being, but unless you are using your monitors under fairly bright
12、lighting (not an ideal situation!) then you probably dont want to calibrate to the lowest of the monitors white luminance, which would be the same process are choosing a target black point, but at the white end. Instead you want to determine the correct target white luminance value for your ambient
13、lighting conditions, and make sure that your ambient lighting is appropriate while you are at it. This means running Spyder2PRO with the optional Ambient Light function activated on at least one of your monitors. If you have done this previously, then you already have determined a reasonable white l
14、uminance and white point values for your conditions. If you have not yet run Spyder2PROs Ambient Light Wizard, you need to do so now, to determine if your room lighting is too bright, and once you have your room lighting under control, to determine the correct monitor white luminance range for your
15、conditions. Compare this value to the native white luminance of each monitor. If any of your monitors cant reach this level, you have a problem, and need to reconsider your ambient lighting levels. If all your monitors have a native white luminance comfortably above the target value, then you are re
16、ady to create a custom target for your monitors. Please note that choosing a white luminance target that is equal to your dimmest monitors maximum will result in a target with a white luminance value which this monitor will no longer be able to reach in a few weeks. So some headroom is required, eve
17、n if your ambient lighting is bright enough that reducing your monitors white luminance isnt necessary to create a balanced ambient-to-monitor ratio. Whitepoint and Gamma targets also need to be considered. For use with color managed applications, you can use most any gamma, though choosing one far
18、from your monitors native gamma can cause visible banding in synthetic gradients on screen. This is one reason for choosing gamma 2.2, which is close to the native gamma of most monitors, or the emulated gamma of most LCDs. Another reason to choose Gamma 2.2 is that it will function best with the ex
19、pectations of non-color managed applications, such as Windows-based browsers. Whitepoint can be determined using the assistance of the Ambient Light Wizard. This will typically be 6500k for moderate lighting, 5000k for very dim lighting, and leaves you the option of a whitepoint in between these two
20、 more dim but not dark ambient lighting. Now that you have target gamma, whitepoint, black luminance and white luminance values that can be achieved by all your monitors, and that are appropriate to your ambient lighting, you are ready to define a new custom target with these values, and choose that
21、 target for calibrating all your monitors. For monitors on other systems, you can copy this target file to the copy of Spyder2PRO on those machines, or simply define a target with the same values there. Once you have determined your target white luminance, its no longer necessary to calibrate with the Ambient Light Wizard on, though you can continue to run it just to check that your ambient lighting is still in the target range. 2007 Datacolor. Datacolor, ColorVision and other Datacolor product trademarks are the property of Datacolor.
