Sample workflows for using previews effectively
There are several methods for using preview images efficiently and effectively:
Generate previews for projects you intend to keep offline: A JPEG preview is displayed when a referenced image’s original is offline or cannot be found. This makes previews a great way of maintaining high picture quality while conserving the disk space that originals (especially RAW files) require.
Generate previews for photos based on rating: Another way to use previews is to create a search that displays only low-rated photos. You can then build previews just for those photos and take their originals offline (for example, burn them to a DVD). That way you still have good-quality images for all of your photos, without using a lot of disk space.
You can also create a search that displays only highly rated photos and then build previews for those photos only. This is a useful alternative for workflows in which the default thumbnail resolution is sufficient for low-rated photos. For more information about searching for photos, see Searching overview.
Generate previews for new or active projects: Because previews are used by the iLife and iWork Media Browsers as well as by the OS X screen saver, you can use previews as a way to distribute your Aperture photos in movies, on the web, on DVDs, in slideshows, and in podcasts using the applications in iLife. You can also download your Aperture photos to devices such as iPad, iPhone, and iPod touch; import your Aperture photos into iPhoto; or use them to create Pages documents.
Generate previews for Smart Albums: You can create previews for photos collected in Smart Albums. For example, you can create previews for highly rated photos only. For more information about working with Smart Albums, see Collect photos in a new Smart Album.
Use previews for offline referenced images
Make sure the external hard disk containing the referenced originals you want to keep offline is connected to your computer.
If the originals you want to keep offline are currently stored on your computer, you must convert the images to referenced images and move the originals to an external hard disk. You can do this by selecting the project containing the photos whose originals you want to keep offline, choosing File > Relocate Originals, selecting an external hard disk location for the originals, and then clicking Relocate Originals.
Select the project containing the photos whose originals you want to keep offline, then choose Photos > Update Previews.
When the previews are built (you can check the status by choosing Window > Show Activity), you can disconnect the hard disk containing the originals.
Even though the originals are offline, you can browse, search, and assign metadata to preview images. You can even use the Loupe to zoom in on preview images, because they are high-quality JPEG files.
Share previews with other applications
Select the project whose photos you want to share with other applications, then choose Maintain Previews For Project from the Library Action pop-up menu .
Choose Aperture > Preferences, then click Previews.
Choose Always or “When quitting Aperture” in the “Share XML with other applications” pop-up menu.
In the Library inspector, select the project and choose Photos > Update Previews for Project.
When the previews are built, you can open any of the iLife and iWork applications and use your Aperture photos.
Generate previews for Smart Albums
Create a Smart Album and specify criteria for it using the Smart Album’s Smart Settings HUD.
Click in the Browser, then press Command-A to select all the photos.
Choose Photos > Update Previews.
Note: Previews for Smart Albums are not automatically maintained—automatic preview maintenance is a project-level setting only. In this workflow, you need to update the previews yourself periodically, by following the steps in Manually manage previews. Aperture builds previews only for the versions that have changed, so you don’t need to determine which ones to update.