New 21.5-inch Retina 4K models expected.
Retina MacBook Pro Users Still Complaining of Image Persistence
Apple was reportedly replacing the affected machines and DisplayMate's Ray Soneira had indicated that it was likely to be an early production issue, but three months later users are still complaining about the issue. Extensive threads in the MacRumors forums and at Apple Support Communities have been tracking the issue, which preferentially affects displays manufactured by LG. Displays manufactured by Samsung do not generally appear to be suffering from the problem.
Example of image persistence after just 10 minutes on screen
Several of the affected users report being on their third or fourth machine and still receiving units that are affected by the issue. But even as Apple is replacing machines showing image persistence, the company has posted a new support document stating that the phenomenon is normal on the in-plane switching (IPS) displays used in the Retina MacBook Pro and other products.
On an IPS display, when an image such as a login window is left on screen for a long period of time, you may temporarily see a faint remnant of the image even after a new image replaces it. This is referred to as "persistence," "image retention," or "ghosting." This is normal behavior for an IPS display, and the faint image will disappear over time.As noted in our forum thread users can paste the following command into Terminal in order to determine the manufacturer of their displays:
You can prevent image persistence by using the display sleep feature to turn off the display when it is not in use. You can also use a screen saver to make sure that a static image isn't on the display for long periods of time. Both of these features are on by default in Mac OS X, but you can adjust the settings as needed.
ioreg -lw0 | grep \"EDID\" | sed "/[^<]*</s///" | xxd -p -r | strings -6
Model numbers beginning with "LP" indicate an LG display while model number beginning with "LSN" correspond to Samsung displays. A number of those affected by the issue indicate that it was not necessarily noticeable at first but has seemed to worsen over time, and a checkerboard image posted to our forums can be used to help assess the severity of the problem. Users with significant issues should, however, be able to easily see the image persistence when moving any window away from a contrasting background after even just a few minutes on the screen.