How To Interpret The Graph

The calibration gives us a DeltaE graph of the monitors. This value corresponds to the measured difference between the requested color and the color actually reproduced. A DeltaE less than or equal to 1 represents a perfect calibration: there is no perceptible difference between the original color and the reproduced one. Starting at DeltaE = 3, the human eye can detect the difference in shade.

On the X-axis: the values go from black (0) to white (100). On the Y-axis is the DeltaE.

Applied to the graph of our Prophetview 920 Pro, this means that:

• DeltaE < 2 = 94% of the colors displayed, from dark gray to white, are correct.
• DeltaE < 1 = 76% of the colors are reproduced perfectly.
• DeltaE > 3 = 4% of the colors displayed are not accurate. This is the case mostly with dark colors on TFT monitors.

This test also shows:

• Contrast level with the calibration adjustments.
• Black depth, with a measurement of black brightness displayed with the same adjustments.
• Brightness under test conditions.

So, using these results, you can judge the "static" quality of the monitors - that is, their ability to display still images precisely. But what about latency?

Measuring Latency

The System

The complete system for measuring latency consists of:

• An optical sensor that converts light intensity into voltage.
• A linear laboratory power supply to power the sensor.
• A digital oscilloscope.
• Stimulation software.

Since this is a specially developed system, we should describe how it operates and performs, in order to rule out any doubts as to the validity of our measurements.