What does the new sensor on the back of the iPad Pro (2024) do?

The 2024 iPad Pro models have some changes. While the OLED displays are probably the most well-known upgrade, not far behind is the inclusion of the new, powerful 3nm M4 chip replacing the M2 that powers the iPad Pro (2022). The front-facing camera is now in landscape orientation, and the number of cameras on the back is reduced from two to one with the removal of the Ultra-wide lens.

However, some iPad Pro (2024) buyers have noticed a mysterious sensor on the back of the tablet. The previous generation iPad Pro model had Wide and Ultra-wide lenses, the LiDar scanner, a microphone, and the LED flash. Per 9to5 Mac, with the redesign, the new version of Apple's top-of-the-line tablet has on the back the aforementioned Wide lens, the LiDar scanner, a microphone, LED flash, and the mysterious sensor.

So what exactly is this sensor, and what does it do? It seems that this is a rear Ambient Light Sensor. You probably are saying to yourself, "Doesn't such a sensor adorn the front of the tablet?" If you're asking yourself that, you'd be 100% correct. The front Ambient Light Sensor is used to control the settings for the automatic brightness feature for the display, and the True Tone setting. The latter uses sensors to adjust the color temperature of the display based on ambient light.

The thinking is that Apple added a rear Ambient Light Sensor to improve the now solo rear camera. During the "Let Loose" event, Apple did state that the M4 iPad Pro models have a new "adaptive" True Tone flash that detects ambient light conditions to make document scanning easier by removing shadows thanks to the combination of hardware and AI. The new Ambient Light Sensor might change the color of the True Tone flash when scanning or taking a photograph of a document.

If this sensor has any other reasons for existing besides improving the capture of documents, Apple has yet to reveal it.