What Is Retina Display?

what is retina display
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Retina Display is the name given by Apple to the high-resolution screen technology used on various models of the iPhone, iPod touch, and other Apple products. It was introduced with the iPhone 4 in June 2010. 

What Is Retina Display?

Retina Display gets its name from Apple's claim that screens made with the technology are so sharp and high quality that it's impossible for the human eye to distinguish individual pixels.

Retina Display smoothes the jagged edges of the pixels that make up images on screens. 

The benefits of the technology are visible in many uses, but especially in displaying text, where curved font edges are substantially smoother than on previous display technologies.

Retina Display's image quality derives from a number of factors:

  • A high density of the pixels that make up the device's screen
  • Higher contrast ratio than previous models to create brighter whites and deeper blacks
  • In-Plane Switching (IPS) technology to improve the angles from which the screen can be viewed
  • Chemically treated glass over the screen and LED backlighting to improve the quality of the image.

The Two Factors That Make a Screen Retina Display 

Here's where things get a little tricky: There is no single screen resolution that make something a Retina Display.

For instance, you can't say that every device with a resolution of  960 x 640 (like the iPhone 4) has a Retina Display.

Instead, there are two factors that create a Retina Display screen: pixel density and the distance from which the screen is normally viewed.

Pixel Density refers to how tightly packed the screen's pixels are. The greater the density, the smoother the images. Pixel density is measured in pixels per inch, or PPI, which indicates how many pixels are in one square inch of screen.

This is based on a combination of the device's resolution and its physical size.

The iPhone 4 had 326 PPI thanks to a 3.5-inch screen with a 960 x 640 resolution. This was the original PPI for Retina Display screens, though that changed as later models were released. For instance, the iPad Air 2 has a 2048 x 1536 pixel screen, resulting in 264 PPI. That, too, is a Retina Display screen. This is where the second factor comes in.

Viewing Distance refers to how far away users generally hold the device from their faces. For example, the iPhone is generally held fairly close to the user's face, while a Macbook Pro is generally held farther away. This matters because the defining characteristic of a Retina Display is that the pixels can't be seen by a human eye. Something that's seen from much closer up needs a greater pixel density for the eye not to see the pixels. Pixel density can be lower for things seen at a greater distance.

Other Retina Display Names

As Apple has introduced new devices, screen sizes, and pixel densities, it has begun to use other names for different Retina Displays. These include:

  • Retina Display—used on the iPhone 4, among others
  • Retina HD Display—used on the iPhone 6 Plus, and others
  • Retina 4K Display—used on the 21-inch iMac
  • Retina 5K Display—used on the 27-inch iMac.

Apple Products with Retina Display

Retina Displays are available on the following Apple products, at the following resolutions and pixel densities:

iPhone

 Screen Size*ResolutionPPI
iPhone SE41136 × 640326
iPhone 6 Plus & 6S Plus5.51920 × 1080401
iPhone 6S & 64.71334 × 750326
iPhone 5S, 5C, & 541136 × 640326
iPhone 4S & 43.5960 × 640326

* in inches for all charts

 

iPod touch

 Screen SizeResolutionPPI
6th Gen. iPod touch41136 × 640326
5th Gen. iPod touch41136 × 640326
4th Gen. iPod touch3.5960 × 640326

 

iPad

 Screen SizeResolutionPPI
iPad Pro12.92732 × 2048264
iPad Air & Air 29.72048 × 1536264
iPad 4 & 39.72048 × 1536264
iPad mini 2, 3, and 47.92048 × 1536326

 

Apple Watch

 Screen SizeResolutionPPI
1st gen - 42mm body1.5312 × 390333
1st gen - 38mm body1.32272 × 340330

 

iMac

 Screen SizeResolutionPPI
with Retina Display275120 × 2880218
with Retina Display21.54096 × 2304219

 

Macbook Pro

 Screen SizeResolutionPPI
3rd Gen.15.42880 × 1800220
3rd Gen.13.32560 × 1600227

 

Macbook

 Screen SizeResolutionPPI
2015 model122304 × 1440226

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