Basic Monitor Calibration
When we display images on the Internet it is impossible for us to know how they will look on your monitor. Factory default settings are never accurate because bright and saturated color, not accuracy, sells monitors.
At the very least it takes specialized software and time to calibrate a monitor with reasonable accuracy. For precision work additional hardware is employed to measure and adjust a monitor's output. In recent years monitor calibration hardware and software packages have become much more affordable. They are definitely worth the investment if you care about color accuracy.
While complete monitor calibration is far beyond the scope of this discussion, a few easy steps can generally get brightness and contrast settings in the right ballpark. It is important to let your monitor warm up for at least thirty minutes before calibrating it. Room lighting can make a big difference in the results. Lights should be dim and there should be no glare on your monitor.
1. Set your monitor's contrast to 100% for CRT monitors and 75% for LCD monitors. Using the charts at the top of this page, decrease the brightness until all of the dark gray rectangles become indistinguishable from the pure black (R=B=G=0) areas beside them. Then slowly increase the brightness until you begin to see the difference between the level 16 rectangle and the pure black area. At this point you should be able to see the difference between most, if not all, of the white rectangles and the pure white area (R=B=G=255) beside them. Note which white rectangles are discernable now. If you cannot differentiate any of the white rectangles from the pure white area beside them at this point, go to step 3.
2. Slowly increase the brightness until you begin to lose, but do not actually lose, the ability to differentiate the brightest white rectangle you could discern at the end of step 1 and the pure white area beside it. Your monitor's brightness and contrast are now properly set. Users of flat panel monitors may want to try this with different contrast settings to maximize the number of white and black squares that are simultaneously visible. Once adjusted, all of the rectangles in the chart below should be plainly visible.
3. Use this method only if you could not differentiate any of the white rectangles from the pure white area beside them at the end of step 1 above. This is an indication that your monitor may be worn out or simply incapable of displaying a wide range of tonality. Here we will try a coarser adjustment to try maximizing what your monitor can display.
With the contrast set at 100% (75% for flat panel monitors), increase the brightness until you can see the difference between the 95% and 100% rectangles below. Decrease the brightness until the 95% and 100% rectangles almost, but not quite, merge together. If you can see a difference between 0% and 5% rectangles at the same time you can see a difference between the 95% and 100% rectangles, your monitor is adjusted. In some cases this will result in a setting that is too bright, causing the 0% and 5% rectangles to merge together. If this seems to be the case, your monitor cannot display all the tones in the chart below at the same time. The best alternative is to decrease the brightness until you begin to see some difference between the 0% and 5% rectangles. This will preserve image highlights but some shadow details in the images you view will be lost.
It is much more difficult for monitors to display small differences in dark areas than it is for them to display small differences in bright areas. The difference between the 0% and 5% rectangles should always be plainly visible, and it should appear as large as the difference between the 5% and 10% rectangles. If this is not the case, your monitor is too bright.
Copyright 1997-2006 Dean M. Chriss
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