Why calibrate?
Barco’s NSL-4601 and LC displays have a factory preset that closely approximates the necessary color temperature of 6500K and gamma of 2.2. However, due to dispersion in backlight properties, variations in color filters and imperfection of the LCD transfer function, any display will deviate from the target in terms of brightness, gamma, color temperature as well as gray tracking. Calibrating the look-up-table of a display to a common target is the only way to achieve the best possible uniformity between displays within the given calibration tolerance.
How does it work?
The LCD displays have their native R, G and B look-up tables and gammas. For a grade-2 display it is not possible to have identical R, G and B gammas without influencing the gray tracking, and vice versa. The DCMS algorithm gets the best out of your display by finding the best possible calibration setting. The calibration loop makes sure that the R, G and B gammas and gray tracking are optimized on at least 8 points throughout the gray scale. The rest is calculated by interpolation. The light output is finally calibrated by adapting the backlight power.
How much does it improve?
The level of improvement depends on the following factors:
- Factory pre-set differences between displays
- The calibration precision and sensor accuracy
- The LCD’s native characteristics
The actual sensor accuracy differs from an ideal spectrometer measurement. We call this the sensor’s bias. This is different for each sensor, and is typically Δ x, y < 0.003. The accuracy tends to shift in time in one single sensor. This only affects the absolute calibration of the display, not the relative calibration setting between multiple displays. The sensor precision is the level to which consecutive measurements have the same outcome. Likewise, consecutive calibrations of one display could yield slightly different results. The precision level of the sensor is typically Δ x, y < 0.003 for D65 calibration. Other factors, such as the LCD’s native characteristics, are impossible to predict.
Two modes of calibration
- Workstation mode: you can install the DCMS on the workstation, and calibrate the display you are working on using a graphical test pattern generated by the software GUI. The display content is not lost during calibration.
- Independent mode: you can calibrate an overview display that is attached to another source generator, by using the internal display test patterns. In this mode you do not have to reconnect signal cables to the display. The display content is lost during calibration.
This product is an option of the following products
