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What Is Apple’s ‘Retina Display,’ and What Would It Do for an iMac?

Daniel Howley
Technology Editor
Yahoo Tech
Comparison of text on an iMac with and without Retina display

Apple, we are pretty sure, is set to unveil a new pair of iPads at its event tomorrow (we’re liveblogging!) It’s rumored to be updating its iconic line of iMac all-in-one computers, too.

And if the rumors leading up to the show are to be believed, one of the biggest phrases of the day will be “Retina display.”

That’s because in addition to the new iPad Air and iPad mini, both of which already feature Retina displays, Apple is expected to launch its first-ever iMac with a Retina display, too.

You might know that the iPhone has a Retina display, as does the most expensive version of the MacBook Pro laptop. With the new iMac with Retina display, however, Apple would be rolling out its largest-ever Retina display.

So now might be a good time to figure a few things out: Just what is a Retina display, and why is having one such a big deal? Let’s take a look.

What the heck is a Retina display?

Apple iPad with Retina display

Basically, “Retina display” is Apple’s term for a screen with a high resolution. Apple uses the term “Retina display” because, as Steve Jobs indicated when the first iPhone with Retina display was unveiled, it has such a high number of pixels packed into such a small space that it is impossible for the average person to discern individual pixels at a normal viewing distance.

But just to be clear, “Retina display” is nothing more than a marketing term. It’s not a universal display standard, and you won’t find it used by any other manufacturer — even if their screens are also at such a high resolution that you couldn’t make out the pixels.

Why would I want a Retina display?
OK, remember those pixels I was just talking about? Well, your screen is made up of thousands of them. Without these little squares, you wouldn’t have an image to look at. When you have a screen with a low resolution, individual pixels are easier to see. As a result, images and text look blurred.

iMac displays

Remember how your first computer monitor made the curved and rounded edges of numbers and text look like they were made of a bunch of tiny square blocks? That’s because the screen had such a low resolution that you were actually seeing its pixels.

Pump up the number of pixels a screen has — Retina displays typically have between 200 and 300 pixels per inch — and suddenly individual pixels are much harder to make out, which in turn means that things like text, numbers, photos, and videos look much smoother and more lifelike.

What’s more, if you’re a photo or video editor, having a high-resolution screen gives you a clearer, more accurate look at your images and videos.

What will the new iMac’s screen look like?
Well, according to the rumor mill, the new iMac will get a 27-inch Retina display. That would be the largest such screen Apple has ever made. The folks over at 9to5Mac are reporting that the iMac will have a resolution of 5120 × 2880 pixels.

iMac displays

That blows away the average TV, which has a resolution of 1920 × 1080. (Hence the “1080p” you so often see advertised with televisions.) With such a high resolution, 9to5Mac says, the iMac’s screen would have a pixel density of 218 pixels per inch (PPI). The current 15-inch MacBook Pro with Retina display has a pixel density of 220 PPI.

Will the new iMac be 4K compatible?
The 4K resolution standard for consumer TVs is rated at 3840 × 2160. If the iMac’s screen resolution does actually come in at 5120 × 2880, it would essentially be a 5K display. That means the iMac could display 4K content.

Do other manufacturers offer 4K displays?
Indeed they do. Companies such as Dell and ASUS already sell 4K monitors, with Dell even selling one for the relatively low price of $449. In other words, Apple isn’t the only company offering such high-resolution displays.

When can I get an iMac with Retina display?
Most of the rumors circulating around the Web point to the iMac landing on store shelves in time for the holiday season or in early 2015. Although there is a chance that the iMac with Retina display could hit stores even sooner.

Email Daniel at dhowley@yahoo-inc.com; follow him on Twitter at @DanielHowley or on Google+ here.