Some Retina iPad minis are demonstrating image retention issues, as noted by Instapaper creator Marco Arment, who originally developed a grid test to detect the problem in Retina MacBook Pros.
Image retention was first cited as a potential issue last week, when a rumor suggested that burn-in on Sharp's IGZO panels was causing production delays with the Retina mini's display, leading to significant supply constraints that have resulted in a quiet release for the tablet.
While it is unclear how many Retina iPad minis are affected by the issue, several mini owners on Twitter have discovered the problem after running the grid test. It is not known if the image retention is limited to displays from specific manufacturers, as many Retina iPad minis are not experiencing display problems.
An example of image retention after running the grid test, via Twitter
Displays with image retention are not a new problem for Apple. The original Retina MacBook Pro displays demonstrated severe image persistence problems, with remnants or previously-displayed windows remaining visible on the screen for several minutes. It is important to note, however, that the image retention is temporary and not permanent like the burn-in seen with some plasma displays.
In normal use cases, it is unlikely that the image retention is noticeable, but Retina iPad mini owners experiencing image retention are still within their return windows. Apple has replaced Retina MacBook Pros experiencing display problems, and it is likely that a similar policy will be adopted for Retina iPad minis with image persistence.
In addition to image retention, some users on the MacRumors forums have also noted that their Retina mini screens are not as vibrant as iPad Air, suggesting the Retina iPad mini may have a smaller color gamut.
Apple's Retina iPad mini is currently available from the Apple Online Store beginning at $399. Orders are currently shipping within 1 to 10 days in the United States depending on capacity and cellular capability, and while Apple has not made the mini widely available in its stores, it is also available in many areas via Personal Pickup.