Apple TV Color Balance Feature May Make Image Quality and Colors Worse
The Apple TV's Color Calibration debuted in tvOS 14.5 and iOS 14.5, giving users the ability to hold an iPhone with Face ID near their TV and, after tapping a notification, the iPhone's front-facing camera and ambient light sensor will begin color measurements and automatically tailor the Apple TV's video output to deliver supposedly more accurate colors and improved contrast. Apple says this process will result in improved picture quality without adjusting the TV's settings.
Teoh found that in a number of cases Apple's calibration feature actually made color accuracy worse, even going as far as to incorrectly shift the color output of a high-end Sony mastering monitor.
When set to their most accurate out-of-the-box color presets, two of the three TVs Teoh tested had their color accuracy made worse. On a Samsung QLED TV, the overall color accuracy improved, but the image was incorrectly shifted to a cooler blue tone. On a Sony LED TV, the feature made the color accuracy worse and similarly made the image too blue. On an LG OLED TV, the calibration feature did manage to improve color accuracy without making the image too blue.
When the tests were re-run with the TV's default color presets, the Apple TV's calibration feature improved color accuracy on all three models. Even so, Teoh found that when color accuracy was improved, image quality was degraded in other ways. Since the Apple TV had to shift the color output so much in these instances, the resulting image suffered from unwanted color banding lines, known as posterization.
Teoh's tests indicate that the Apple TV's color calibration is certainly not a replacement for professional color calibration using specialized tools, and should be used with caution. AFTVnews suggests that users may be better off using the Color Balance feature to see how drastically it changes the TV's image, and then attempting to match the result using the TV's built-in color options.