What is the most effective way to check a monitor's contrast?

The most effective way to check a monitor's contrast is by utilizing gray squares inside white or black patches on a test pattern. This method allows for a direct visual comparison between various shades of gray and the surrounding colors. By assessing the visibility of these gray squares against the contrasting patches, one can determine how well the monitor can display a range of tones from light to dark. This technique provides a clear indicator of the monitor's ability to differentiate between subtle changes in contrast, which is essential for accurate image interpretation in diagnostic imaging. Utilizing a test pattern with these elements allows the viewer to quickly identify any issues with the monitor's contrast performance.