Force OS X Finder to always show dimensions of images in sidebar
Solution 1:
You might need to re-index the directories on your system by doing the following:
- Go to
Apple > System Preferences > Spotlightand chose thePrivacytab. - Drag a directory (or an entire volume) into the list, and confirm the action
- Remove the directory (or volume) from the list via
-it, which will trigger a re-index of the directory or volume.
Source