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by ned 5167 days ago
No, the distinction of device pixels vs. CSS pixels predates the first "Retina" iPhone. The distinction existed in all browsers supporting full page zoom, including the Safari on the first iPhone, and in Opera for years before that.

"Retina" is just a marketing term for "pixels so small your eye can't distinguish them at a normal distance anymore".
1 comments
goblin89 5167 days ago
The distinction is also in CSS specs[0] since version 2.1: “The reference pixel is the visual angle of one pixel on a device with a pixel density of 96dpi and a distance from the reader of an arm's length. <…> 1px thus corresponds to about 0.26 mm (1/96 inch).”

[0] http://www.w3.org/TR/CSS21/syndata.html#length-units

See also http://inamidst.com/stuff/notes/csspx (been featured on HN some time ago)

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drcube 5167 days ago
Why are their visual angles measured in millimeters?
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