What does the Retina display on the Apple iPad actually mean?
The technical specifications for the Apple IPad with retina display lists the following attributes: 264 PPI, 69 PPD, and a resolution of 2048 x 1536 with an optimal viewing distance of 15 inches. So, what is retina display on IPad? The retina display supplies the IPad with a clear and crisp viewing area that is capable of displaying images and text smoothly without jagged edges. How the retina display manages this is quite the complicated task.
The first attribute, PPI, is an acronym for pixels per inch. 264 PPI signifies that each inch within the display contains 264 picture elements. Each element is comprised of blue, red and green light-emitting diodes, also known as LEDs. When an image is created on an LED display each pixel employs these diodes to create a specific color by combining shades of red, blue and green.
Every color, shape, and image on this web page is created on digital devices with these pixels. Typically, cramming so many pixels into such a confined space creates noise from the electrical signals which will cause blurry and discolored images. Apple dampens this noise by layering the pixels in a tier which raises the pixels away from each other. This process preserves the integrity of the densely packed pixels.
Degree represents the angle with which a user views the IPad. The degree, angle and viewing distance are used to calculate the optimum number of pixels needed to create the illusion of a perfectly clear display based on the viewer’s angle and distance. 69 PPD signifies that a density of 69 pixels per degree is perceived by the human eye as ideal on a display that is approximately 15 inches away and has a width of 2048 pixels and a height of 1536 pixels.
The retina display of the Apple IPad uses approximately 3 million pixels with 264 pixels per inch and 69 pixels per degree to provide a clear, crisp image that is perceived as flawless. While 15 inches is the ideal distance, the display will still be excellent at closer ranges due to the pixels per degree.