Samuel Gibbs describes Apple’s iMac with 5K Retina display.
The iMac with 5K retina display is Apple’s attempt to do what it did with smartphones and tablets and redefine what a computer screen should be. If so it has hit a home run… The new iMac has a 5K screen, exactly double the resolution of the non-5K 27in iMac, with 5120 x 2880 pixels. That is seven times the number of pixels on screen compared to a 1080p full HD television screen. But those are just numbers, what it really means is that the screen is super crisp; as sharp as a modern smartphone screen.
The iMac automatically detects the type of content on screen and displays it at the correct resolution. Photos and video is played at native resolution. For text, however, four pixels are displayed for everyone one defined by the site. The text remains the same size on screen but is pin sharp. This is the same system Apple has been using on its iPhones, iPads and retina MacBook Pros for years.
You need to see it to believe it, but the screen is crystal clear, huge, inviting, and icons pop with clarity. It’s the best Mac I’ve ever owned.