One of the most interesting new features added recently to the new Apple TV 4K and the previous generation is the ability to calibrate the screen using the front sensors on an iPhone. Professional television calibrator Vincent Teoh, who runs the great YouTube channel HDTVTest has put the new Apple TV calibration feature through its paces in his latest video. He found that in several cases the Apple TV calibration feature made color accuracy worse, even going as far as to shift the color output of a $40K mastering monitor used by the film and broadcast industry as a reference. In some cases where the calibration feature did improve color accuracy, it degraded the image quality in other ways.

In addition to testing the Apple TV’s calibration feature on a Sony BVM-HX310 mastering monitor, where it shouldn’t have adjusted the image at all but did make it worse, Teoh also tested it on a Samsung Q80T QLED TV, a Sony X900H LED TV, and an LG C9 OLED TV. On the Samsung QLED TV, he found that while it did improve the overall color accuracy, it incorrectly shifted the image to a cooler bluer tone. On the Sony LED TV, the feature made the color accuracy worse than the TV’s factory setting and also made the image too blue. Lastly, on the LG OLED, the calibration feature did the best job by improving color accuracy and not making the image cooler, however, Teoh points out that it’s “nowhere near the accuracy of a properly conducted calibration using specialized tools.” The factory image of the LG OLED had an average delta error value of 3.5 which was improved to 1.94 by the Apple TV’s calibration, while professional calibration brought that down much further to 0.78.

All of the above tests were done with the TVs set to their most accurate out-of-the-box presets, such as Samsung’s “Film Maker” mode and LG’s “Technicolor Expert” mode. Teoh reran the tests on the TV’s default “standard” preset modes, which are far more inaccurate to begin with, and found that the Apple TV’s calibration feature did improve color accuracy across the board. However, since the streaming device needed to shift the color output so much, it ended up degrading the image quality in other ways. While colors were more accurate after running the Apple TV’s calibration, the resulting image suffered from posterization, which is the appearance unwanted color banding lines, not seen in the original uncalibrated image.

The takeaway here is that the Apple TV’s color calibration feature is certainly not a replacement for professional TV calibration. Even if professional calibration was never a consideration for you, don’t blindly trust the feature to make things better all around. You’re probably better off using the feature to see how drastically it changes the image and then trying to match the result, assuming you like the change, using your TV’s built-in image adjustments. The additional advantage there is that the improvements will be seen on all TV inputs and content, not just on the Apple TV.