Demonstration of an "image retention" (IR) problem with a brand new 27" iMac (late 2012 model) received in early January 2013. Some bright images on the screen will leave behind ghost "after images" when replaced by a darker image or background. 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.
Apple is sending a replacement, which I will thoroughly check for IR as soon as I get it.