15
Minimum Brightness Limit
The factory set minimum brightness is approximately 250 cd/m2. In most applications the factory setting is desired to maintain the widest dimming range possible. But for applications where 250 cd/m2 is too low but some dimming is still desired, the minimum brightness limit may be increased. The OSD controls are used to access and change the minimum brightness limit setting, as described in the User Controls section of this manual.
Below is a graph showing the typical minimum brightness limit for a given OSD setting:
To change the minimum brightness limit, one of three basic methods can be used:
1.If one wishes to set an approximate minimum brightness, the above graph may be used. For instance, to set the minimum to typically 400 cd/m2, set the minimum brightness limit to an OSD setting of 25. Note, however, that there may be significant (+/- 50%) luminance variation for a given OSD setting due to display variation.
2.To set the minimum brightness visually, one may set the dimming to a minimum (by covering the photo sensor on the front of the monitor if in automatic brightness control mode, or by setting the DIM_INPUT to 5V if in manual brightness control mode) and then adjust the OSD setting to visually give the desired result.
3.To quantitatively set the minimum brightness to a desired luminance, one may set the dimming to a minimum and then adjust the OSD setting to give the desired result as measured by a photome- ter (such as the Tektronix J17 with a J1803 luminance head.) Note that a ten minute
monitor warm up period with the monitor set near its minimum brightness is recommended to allow for an accurate measurement.
