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Adjusting Multi-Point Grayscale for TV Calibration

August 3, 2020

Multipoint grayscale calibration uses a series of white balance controls to correct the display’s red, green, and blue output at multiple brightness levels. Most displays offer either 11-point (10% increments) or 21-point (5% increments) grayscale controls, with independent red, green, and blue adjustments at each point.

Many displays also include a standard 2-point white balance adjustment. It is strongly recommended to complete the 2-point calibration first, as it establishes a stable foundation before fine-tuning with multipoint controls.

Calibrating more points provides finer control and allows you to correct subtle errors across the grayscale range.

Note:

For multipoint calibration, both RGB Balance charts in Calman must be set to Absolute mode.

To switch to Absolute mode:

  • Right-click each RGB Balance chart → Properties → under Reference, select Absolute.

Multipoint Grayscale Calibration Procedure

  1. Prepare your environment
    • Ensure your meter and test pattern source are correctly configured in both Calman and on the display.
  2. Select the calibration point density
    • Go to Calman Settings → Workflow Basic Options → Grayscale Points and choose the appropriate number of points for the display.
  3. Measure initial grayscale tracking
    • On the Grayscale Calibration page, click Read Series to capture the display’s current grayscale performance.
  4. Begin point-by-point calibration
    • Use the Pattern Slider at the bottom of Calman to choose the 100% grayscale point.
    • Click Read Continuous to begin live measurements.
    • On the display, enter its 10- or 11-point white balance controls and select the 100% (100 IRE) adjustment point.
    • Adjust the display’s red, green, and blue controls so all three channels align with the 100 target line on the Single Level RGB Balance chart.

      • In this example, the Red and Blue channels may need to be reduced to balance with Green, or Green may be able to be increased to balance, depending on display support.
  5. Repeat for each grayscale level
    • Move through the remaining adjustment points (e.g., 95%, 90%, 85%, etc.) and balance RGB at each level until all points track as closely as possible to the 100 target line.
  6. Verify results
    • When all points are adjusted, run another Read Series to evaluate overall grayscale tracking.
    • Review the full RGB Balance chart for uniform tracking.
    • A DeltaE of 1.0 or lower is typically not visible in real-world viewing.