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Retina Display2:11 with Amit Bijlani
A Retina display is a liquid crystal display branded by Apple. The pixel density is so high that the human eye cannot discern pixelation at a normal viewing distance.
You've heard the term, the iPad has it, it was first introduced with the iPhone 4, and now even the MacBook Pro has it,
so what is it really, and how does it affect you as a developer?
What am I talking about? Well it's the retina display.
I know you have a lot of questions. Firstly, what is it?
It's a display technique to give you crisp, clear quality, almost close to 20/20 vision as you see in real life,
which means they take a really high-resolution image and condense it within the display.
Remember they don't scale this image. They just use more pixel data to show a finer level of detail so you don't see individual pixels.
Still don't get it? Don't worry. Let's talk pixels.
The original iPhone had a 3.5 inch screen which required images to be sized 320 x 480 px.
With the iPhone 4 came the retina display which maintained the screen size,
but now for crisp, clear quality you had to create an image twice the size which means an image of 640 x 960 px
to support the retina screen
and then scale down to 320 x 480 px to support the standard screen.
The iPhone 5 came with a taller screen of 4 inches.
A taller screen means that you need a taller image.
The retina version of this image would be 640 x 1136 px and scale down to 320 x 568 px for the standard screen.
Even though there are pixel differences in the image sizes, the placement of controls is always in points.
The points bring consistency through various devices, so a button placed at 20 points by 200 points
remains consistently placed at the same X and Y locations whether it's an iPhone 4 or an iPhone 5.
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