Do you think that the new MacBook Air 2020 (here the review of macitynet) does not allow to adequately raise the brightness of the screen? Install Windows and you can change the brightness by increasing it much more than Apple does with macOS.
To report this curiosity are the editors of the site Notebookcheck who measured a 30% difference depending on whether the computer is running macOS or Windows. With macOS there is a brightness equal to 415 nits, in line with what Apple has stated in the specifications (400 nits), but with Windows 10 (installed in an internal disk partition using Boot Camp), the result changes: 547 nits.
Why Apple should block the maximum brightness of MacBook Air 2020 unclear; one of the reasons may be the need to standardize the maximum brightness obtainable, regardless of the display used. Apple could exploit different suppliers for the displays. A second reason could be related to color fidelity; the Notebookcheck website reports that, in effect, using Windows the lower color fidelity.
Another explanation still simply linked to autonomy: the reduction in brightness actually allows you to recover a little autonomy, a parameter that in some conditions can be fundamental. Finally, another possible explanation, that of differentiating MacBook Air from the MacBook Pro 13 ″: the latter screen offers brightness of 500 nit even from macOS, without having to start Windows.
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