Craig Federighi comes clean on how Night Shift avoids ghosting artifacts when scrolling

iOS 9.3 Night Shift

Night Shift, a feature that was introduced in iOS 9.3, reduces the amount of blue light emitted from the display of your iOS device at night to help avoid disrupting your sleep cycle. In helping you getting a good night’s sleep, the feature looks at your geographical position and the time of the day to shift the colors to the warmer end of the spectrum.

But we all know that. Today, we learn that Apple’s engineers also built this feature in a way that avoids ugly artifacts that could appear on LCDs while scrolling and animating.

A customer from Germany emailed Craig Federighi, who is Apple’s Senior Vice President in charge of Software Engineering, to complain about Night Shift mode potentially emitting more blue light than F.l.ux, an iPhone app that serves the same purposes like Night Shift but was banned from the App Store following the release of iOS 9.3.

He received the following reply:

Given the display technology we push it as far as we can without introducing major red ghosting artifacts when scrolling / animating. (Unfortunately, the red phosphors in the LCD hold their color longer and when we shift the display too far into the red then scrolling results in irritating ghosting artifacts).

Here’s our video walkthrough of Night Shift Mode on iPhone and iPad:

To learn more, check out our Night Shift technology overview:

Night Shift Mode only works on 64-bit devices with iOS 9.3 or later.

It’s unsupported on the iPhone 5, iPhone 5c, iPhone 4s and earlier, fourth-generation iPad and earlier, fifth-generation iPod touch and earlier and the original iPad mini. Night Shift may be coming to the Mac, Apple Watch and CarPlay in the future.

Source: (Google Translate)