BEWARE people... This "image retention" thing is STILL very much an issue. Just google "iMac image retention" or "iMac image persistence" and you will get an eye full. I have had 2 late 2013 27" iMacs and both had these issues. I don't know what to do as I just returned the last one to the Apple Store. Do I wait until June and pray that Apple has made LG fix these issues? I am even reading that the 5k models are plagued by this and not just the 2012 and 2013 models. What is most troubling to me is that Apple is calling this "normal". This is NOT normal and has not always happened. I have had many many iMacs since they're very first release and they did not all do this. I spoke to a senior adviser today that said Apple is calling this normal for IPS displays over time... Mine have done it 20 minutes out of the box. I asked him his honest opinion and even he said that he agrees that it is not normal and should not be happening. There is nothing normal about an image burning into your screen...
Apple refers to IR as "image persistence". To the eye this can appear very similar to permanent screen burn-in seen on old CRT or plasma displays, but it's not the same problem. Notes:
- This doesn't happen until the computer has had a chance to warm up.
- The after-images are most visible on a dark gray background, and are invisible against a very bright or completely black background.
- When the problem first starts to kick in as the system warms up, blue after-images show up first, followed by green.
- Certain white or yellow colors result in green after-images.
- Certain blue, magenta, or white colors result in blue after-images.
- Green after-images are far more common than blue after-images.
- Green after-images are much more noticeable/distracting/annoying.
- After system is warm, it takes about two minutes for an after-image to become noticeable, and it becomes strongest after about 5 minutes.
- It takes about 20-30 minutes for a strong after-image to fade away after switching to a dark gray background.
- Rebooting doesn't clear an after-image.