December 1, 2007
Chairman Gruber tackles the issue of text antialiasing on the iPhone (yes, some people actually care about this sort of stuff. Turn outs, I may be one such person). The issue has been whether the iPhone does standard greyscale antialiasing, or colour-fringing subpixel antialiasing.
Gruber concludes that it's standard greyscale. This makes perfects sense, because subpixel shenanigans depends on the renderer knowing the arrangement of the display elements. While the iPhone renderer clearly could know this, it would also have to cope with the screen rotating. So… what does it do? Does it switch from horizontal-subpixel rendering to vertical? Surely that would mean the look of the type changed subtly between portrait and landscape modes? Which might be fairly ghastly.
If you run with standard antialiasing you don't have these problems; a pixel is just a pixel, and the problem doesn't arise. As long as the pixels are square, of course (that's a problem that's still causing problems with web video, incidentally).
Besides, is it just me who hates the colour fringing with subpixel antialiasing? I turn it off on my Macs – can't bear it. Perhaps I'm particularly sensitive to chromatic aberration effects or something, but that little outline of colour speckle makes my eyes crawl.
(Oh, and yes, I turn it off on my Windows boxes too. I know people speak very highly of ClearType, but I think it looks at least as dreadful as 'best for LCD' on OS X.)