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Very interesting. Apparently we can make images clearer by shifting the red half a pixel to the left and the blue half a pixel to the right (very roughly speaki

Very interesting. Apparently we can make images clearer by shifting the red half a pixel to the left and the blue half a pixel to the right (very roughly speaking; I know there is more to it than that). What's up with that? Can anyone find/give an explanation of this phenomenon? EDIT: This guy Miha is amazing. Check out this tiny little font he is working on (go to nearly the bottom of the page for a more complete version): http://typophile.com/node/61920 http://typophile.com/node/61920

anigbrowl 17y ago
It's from a phenomenon known as chromatic aberration which is a characteristic of lenses, including the one in your eye (more so if you have astigmatism). Have you ever looked at someone silhouetted by a bright light, and noticed color fringing on the left and right sides? That's the reason (if you haven't, you have very good eyes). It's also something you often see on photos from cheap digital cameras, where it is introduced by cheap lenses shining onto tiny sensors: http://en.wikipedia.org/wiki/Chromatic_aberration http://en.wikipedia.org/wiki/Chromatic_aberration Interestingly, if you look at the typophile page through a vertically-oriented prism, you'll see similar color fringing on both images - the giant red and white 'pixels' in authentic favicon will shift towards...yellow and purple. Make sure you are looking through the second rotation of the prism - the first rotation does not induce color fringing but reverses left and right instead. edit: Also, someone should hire that guy, like now.
- ars 17y ago
  No, I'm sorry, but none of what you wrote is correct. The color fringing is due to an effect similar to a diffraction grating. It's caused by light bending as it travels near an edge (like a prism makes a rainbow by bending light). Chromatic aberration exists, but has nothing to do with the color fringing. The color fringes on the icon are clearer because an LCD monitor actually has 3 times as many pixels as the typical count. It has 3 pixels for each normal pixel: one for Red, Green, and Blue. These images make use of that, to basically have 3 times the resolution of an ordinary image. So smaller details are now visible. It doesn't work on CRT's (it actually looks worse). And it only works on LCD's if the order of the sub-pixels is the same as what the author expects.
  - anigbrowl 17y ago
    Don't be sorry, I was wrong. Diffractive lenses are used in camera lenses to correct chromatic aberration from refractive lenses, so I sloppily equated the two. Thanks for your clear explanation! It is true about the prismatic color-shifting, though - I have one on the desk so that was an observation rather than a hypothesis.

anigbrowl 17y ago

It's from a phenomenon known as chromatic aberration which is a characteristic of lenses, including the one in your eye (more so if you have astigmatism). Have you ever looked at someone silhouetted by a bright light, and noticed color fringing on the left and right sides? That's the reason (if you haven't, you have very good eyes). It's also something you often see on photos from cheap digital cameras, where it is introduced by cheap lenses shining onto tiny sensors: http://en.wikipedia.org/wiki/Chromatic_aberration http://en.wikipedia.org/wiki/Chromatic_aberration Interestingly, if you look at the typophile page through a vertically-oriented prism, you'll see similar color fringing on both images - the giant red and white 'pixels' in authentic favicon will shift towards...yellow and purple. Make sure you are looking through the second rotation of the prism - the first rotation does not induce color fringing but reverses left and right instead. edit: Also, someone should hire that guy, like now.

ars 17y ago
No, I'm sorry, but none of what you wrote is correct. The color fringing is due to an effect similar to a diffraction grating. It's caused by light bending as it travels near an edge (like a prism makes a rainbow by bending light). Chromatic aberration exists, but has nothing to do with the color fringing. The color fringes on the icon are clearer because an LCD monitor actually has 3 times as many pixels as the typical count. It has 3 pixels for each normal pixel: one for Red, Green, and Blue. These images make use of that, to basically have 3 times the resolution of an ordinary image. So smaller details are now visible. It doesn't work on CRT's (it actually looks worse). And it only works on LCD's if the order of the sub-pixels is the same as what the author expects.
- anigbrowl 17y ago
  Don't be sorry, I was wrong. Diffractive lenses are used in camera lenses to correct chromatic aberration from refractive lenses, so I sloppily equated the two. Thanks for your clear explanation! It is true about the prismatic color-shifting, though - I have one on the desk so that was an observation rather than a hypothesis.