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Date Created: 2/14/2006   Date Modified: 5/23/2016

+Set Contrast and Brightness - What's Going On?

Below is a description of what occurs in the "calibration" portion of the "Calibrate and Profile" workflow for LCD monitors:

  • On the "Measure Maximum Contrast" page, you should have the LCD monitor's contrast control (if present) set to the maximum and the brightness set to the minimum. When you click the "Measure" button, an alternating series of white and light gray patches will be displayed and measured. If the instrument does not detect enough difference between the white and light gray patches, then the contrast control is introducing highlight clipping. In this case, the next page will be the "Set Contrast" page. If no clipping is detected, then the next page will be the "Measure Maximum Brightness" page.
     
  • After clicking the "Measure" button on the "Set Contrast" page, the software will continuously measure the same alternating white and light gray patches and compare them. The position of the indicator on the bar denotes the difference in luminance between the last measured pair of white and light gray. The right edge of the green band and anything to its left is not clipping and considered "safe." When making adjustments during this process, the indicator will jump around. This is because any changes will occur between patch measurements and give a false report until the adjustments have stopped and the software has measured a stable pair of patches. You can also conduct this test visually: watch the measurement area and see if you can see the white patch change to light gray and back. If you can, then highlight clipping should not be a problem and you can proceed to the next step.
     
  • The "Measure Maximum Brightness" has you set the monitor's brightness control to maximum while leaving the contrast control as it was set previously. The same comparison of white and light gray will occur when you press the "Measure" button. If the difference between the white and light gray luminance is too small, the next page will be the "Set Brightness" step. If there is adequate difference, ie: no highlight clipping, the user is taken to the "Adjust Brightness for Room Lighting" page.

  • The "Set Brightness" page functions the same as the "Set Contrast" page, except the user is directed to reduce the monitor's brightness control until the indicator falls within the "Good" range. The same rule applies that anywhere from the right edge of the indicator to the left edge is a safe setting. You can also make the determination visually, based on a visible difference between the white and light gray patches displayed in the measurement square.
     
  • Upon reaching the "Adjust Brightness for Room Lighting" page, the user will have set the monitor's contrast and brightness controls to their maximum setting that does not introduce highlight clipping. The controls should not be set higher than they are now. From here, the software will guide you in setting the brightness of the display that is reasonable for your environment. Upon clicking the "Measure" button, the software will continuously measure a white patch so you can adjust the brightness control until the indicator falls within the green range. When you have the brightness set properly, click the "Done" button and proceed to the "Measure Color Patches" page.