I'm using a Core2Duo Mac mini with the latest OS X 10.6 version. Though the option "Use LCD font smoothing when available" is selected in the System Preferences, Appearance page, when I take a screenshot and zoom-in only gray text is shown, no colored borders on the fonts.

How I can activate LCD sub-pixel antialiasing on OS X 10.6?

  • Do you actually have an LCD connected? Do you have subpixel anti-aliasing when zooming into the GUI by using Ctrl-Scrollwheel?
    – Daniel Beck
    Jun 29, 2011 at 18:12
  • Sure, I have an LCD connected. No, subpixel anti-aliasing is not active when zooming in.
    – Mike L.
    Jun 30, 2011 at 5:56
  • Strange. My is on, and it works, but if I turn it off, it is still there. Perhaps this is a setting that takes affect after you logout and back into your account? You hadn't stated so, but perhaps just logging out of your account then back in will fix it?
    – mkoistinen
    Jul 2, 2011 at 22:32

3 Answers 3


OK, I've found the solution at welp's blog: just execute following command

defaults -currentHost write -globalDomain AppleFontSmoothing -int 2
  • And this changes how it looks on Screenshot?
    – bot47
    Oct 31, 2016 at 17:01

Actually I don't see a difference neither: With LCD smoothing turned on: Turned on

With LCD smoothing turned off: Turned off

If you look at the 'y' you clearly see that the subpixels have all the same brightness. Thus they are just shades of grey.

  • When I get some spare time, I might recheck that and compare it to ClearType
    – bot47
    Jun 29, 2011 at 15:02
  • Don't need to take a photo of your monitor. Just make a screenshot of, e.g., the Preferences dialog and zoom in. If the text of controls is shown only in gray scale, it is no sub-pixel anti-aliasing, if it appears somehow colored at the borders, sub-pixel anti-aliasing is active.
    – Mike L.
    Jun 29, 2011 at 17:16
  • Not necessarily! There can be a difference between the frame buffer and the screenshot rendering. And also, I understood you as if you asked about LCD subpixel antialiasing and that's what I tried to answer with that post. Beside all that, a photography of the monitor is as good as a screenshot. Actually it is more a screenshot than a screenshot is!?
    – bot47
    Jun 29, 2011 at 17:45
  • I reached this question searching for how to take a screenshot that shows subpixels… looks like I'll have to buy a good camera to take a photo of the monitor! Oct 31, 2016 at 16:35
  • This was done using retro photography as in "Mount the lens wrong side round".
    – bot47
    Oct 31, 2016 at 17:00

Sub pixel anti-aliasing is a technique applied at the time of rendering, but it is not part of the original source data.

It is intended to provide a better visual approximation of the source material.

There is more information on the Wikipedia page, but you'll note especially that the non-idealized screenshots at the bottom of the article are taken using a digital camera.

  • 2
    I know what sub-pixel anti-aliasing is. I just want to know how I can activate it on OS X.
    – Mike L.
    Jun 29, 2011 at 17:15

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