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

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.