OLED iPad Pro owners discover grainy display problem

New M4 iPad Pro owners are complaining about an issue that produces visible grainy artifacts in the display.

The iPad Pro with M4 is starting to arrive with consumers, eager to get started using their new tablets. But while the Tandem OLED system promises a bright picture, some users are discovering apparent issues with the display.

For some Reddit users, there appears to be a grainy appearance when viewing content. The grain is visible and very apparent when closely inspected, especially in dark rooms.

In one set of screenshots submitted to the site, the grain was quite visible when viewing dark menu elements.

Grainy screen example on an iPad Pro [Reddit]

While there is seemingly some issue with the displays, it may not be a big deal for many buyers of the iPad Pro. By needing to purposefully look for the grain, it becomes a problem for only a small percentage of device owners.

Possible Mura effects

There is no official comment from Apple about the user reports as yet, so it is unclear exactly what is causing the problem. However, it could be what is known as the Mura effect, or clouding.

The Mura effect refers to an irregularity between pixels, often caused by the screen not being properly illuminated. For example, if a pixel receives too little voltage, it may vary in appearance from another next to it.

The effect is especially present in LCD screens, which rely on backlighting, as well as self-illuminated pixels of OLED panels.

There are a few main reasons why Mura occurs, with it largely revolving around manufacturing. With displays made from multiple layers, sometimes they can be laid in ways that are less than perfect.

It's also possible that some form of contamination occurred during production, again affecting crystals in an OLED panel.

Mura is a very common problem that appears across multiple manufacturers and suppliers, and is often unable to be avoided. In many instances, Mura effects are not really considered as a defect of the display panel.

With the instances happening in dark UI elements, it seems likely that it is a Mura problem. However, it's unlikely that Apple will have an immediate fix for the problem in the short term.