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I've understood that technically the main idea of "retina" is that the physical display pixels no longer map one-to-one with the logical user interface (CSS) pi

by kennu 15y ago

I've understood that technically the main idea of "retina" is that the physical display pixels no longer map one-to-one with the logical user interface (CSS) pixels. Instead, the retina display appears as a virtual low-resolution screen that is able to utilize higher-resolution images (which would otherwise be scaled down). So in this sense, I would claim there is a clear technical difference between just higher-resolution screens (more pixels) and retina displays (same pixels but "better looking"). To me this virtualization of pixels seems like a good idea, since the majority of web pages assume pixels have certain DPI range. Operating systems like OSX treat pixels as floats anyway, so if you need subpixel accuracy, it's still possible.

ned 15y 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".
- goblin89 15y 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 http://www.w3.org/TR/CSS21/syndata.html#length-units See also http://inamidst.com/stuff/notes/csspx http://inamidst.com/stuff/notes/csspx (been featured on HN some time ago)
  - drcube 15y ago
    Why are their visual angles measured in millimeters?
mgunes 15y ago
It's called resolution independence, and has been built into various toolkits and operating systems well before the first "Retina" device. https://en.wikipedia.org/wiki/Resolution_independence https://en.wikipedia.org/wiki/Resolution_independence
- kennu 15y ago
  This becomes about semantics, then. If somebody writes an article about "retina displays", I immediately assume it's about this particular way of implementing resolution independence in the browser and in the OS (by doubling/quadrupling the physical resolution while keeping the virtual resolution the same). So as such it serves me better than a generic term that requires additional explanation.
  - ajross 15y ago
    Uh... of course it's about semantics. What josteink was complaining about was the use of a proprietary marketing term to refer to something technical. Your interpretation is a fine one, but it's not the one that everyone shares. Specifically, it's not the sense that Apple uses the term either. Take a look at Apple's marketing page for the retina display and see if you can find anything about "resolution independence" at all.
    - kennu 15y ago
      So I guess the title of the article should be "Resolution independent high-resolution graphics for your website" then. Retina still communicates the subject better to me, since we all know this is about providing high-res images for iOS devices with Retina displays. Maybe I'm just getting too old to be anal about terminology like this.

by kennu 15y ago

ned 15y 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".

goblin89 15y 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 http://www.w3.org/TR/CSS21/syndata.html#length-units See also http://inamidst.com/stuff/notes/csspx http://inamidst.com/stuff/notes/csspx (been featured on HN some time ago)
- drcube 15y ago
  Why are their visual angles measured in millimeters?

mgunes 15y ago

It's called resolution independence, and has been built into various toolkits and operating systems well before the first "Retina" device. https://en.wikipedia.org/wiki/Resolution_independence https://en.wikipedia.org/wiki/Resolution_independence

kennu 15y ago
This becomes about semantics, then. If somebody writes an article about "retina displays", I immediately assume it's about this particular way of implementing resolution independence in the browser and in the OS (by doubling/quadrupling the physical resolution while keeping the virtual resolution the same). So as such it serves me better than a generic term that requires additional explanation.
- ajross 15y ago
  Uh... of course it's about semantics. What josteink was complaining about was the use of a proprietary marketing term to refer to something technical. Your interpretation is a fine one, but it's not the one that everyone shares. Specifically, it's not the sense that Apple uses the term either. Take a look at Apple's marketing page for the retina display and see if you can find anything about "resolution independence" at all.
  - kennu 15y ago
    So I guess the title of the article should be "Resolution independent high-resolution graphics for your website" then. Retina still communicates the subject better to me, since we all know this is about providing high-res images for iOS devices with Retina displays. Maybe I'm just getting too old to be anal about terminology like this.