Apple MB673Z/A User Manual - Page 198

 Preview Quality: Use this slider to determine the compression setting used for the JPEG previews. The scale ranges from 0 (very high compression and relatively low quality) to 12 (very low compression and relatively high quality). The lower the quality setting, the less disk space a preview uses.  Limit preview size: Choose the size (width and height in pixels) of preview images from this pop-up menu. The default setting is Fit within 2560 x 2560. The "Don't limit" setting tells Aperture to make each preview the same size as the version. The other choices limit the preview to a size no larger than the specified size. A preview is never wider or taller than the version from which it is made. Aperture places asterisks (*) next to choices that match the resolution of your currently connected displays. Not all display resolutions are offered in the pop-up menu, so you may not see any asterisks here. Note: Changing the preview quality and size settings does not affect previews that have already been generated. If you want to regenerate previews using the new settings, you must use the methods described in the following sections. Controlling Previews with the Project Action Pop-Up Menu You enable or disable automatic preview maintenance either on a project-by-project basis or for all projects in a library. To have Aperture automatically update previews in the library: 1 In the Projects inspector, select Library. 2 Choose Maintain Previews For All Projects from the Project Action pop-up menu (with a gear icon). Aperture enables automatic preview maintenance for each project in the library. Aperture will now automatically update previews when images are imported into projects in the library, as well as when versions are created or adjusted. For new projects, Aperture examines the application preference described earlier ("New projects automatically generate previews"). At the library level, a checkmark by the menu item indicates that the setting is enabled for all projects (or for the selected project). A dash (-) indicates that some projects have their previews maintained and others don't (a mixed state). Finally, if neither a checkmark nor a dash appears, automatic preview maintenance is disabled for the entire library. Note: Enabling this setting does not generate the previews. It only tells Aperture what to do the next time an image is imported or a version is created or adjusted. To generate previews, you can use the shortcut menus described below. You can also have Aperture update previews on a project-by-project basis. 198 Part II Photo Editing