Operation Manual

If you encounter performance issues, you can check the Activity window to see if Aperture
is doing work in the background (choose Window > Show Activity). If you think that
preview processing may be degrading performance, you can turn off automatic preview
maintenance for that project and cancel the preview processing task underway. You can
then generate the previews at a more convenient time.
Sample Workflows for Using Previews Effectively
There are several methods for using preview images efficiently and effectively.
Generating Previews for Projects You Intend to Keep Offline
A JPEG preview is displayed when a referenced image’s master is offline or cannot be
found. This makes previews a great way of maintaining high picture quality while
conserving the disk space that masters (especially RAW files) require.
To use previews for offline referenced images
1 Make sure the external hard disk containing the referenced masters you want to keep
offline is connected to your computer.
If the masters you want to keep offline are currently stored on your computer, you must
convert the images to referenced images and move the masters to an external hard disk.
You can do this by selecting the project containing the images whose masters you want
to keep offline, choosing File > Relocate Masters, selecting an external hard disk location
for the masters, and then clicking Relocate Masters.
2 Control-click the project containing the images whose masters you want to keep offline,
then choose Update Previews from the shortcut menu.
3 When the previews are built (you can check the status by choosing Window > Show
Activity), you can disconnect the hard disk containing the masters.
Even though the masters 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.
Generating Previews for Images Based on Rating
Another way to use previews is to create a search that displays only low-rated images.
You can then build previews just for those images and take their masters 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 images and then build previews
for those images only. This is a useful alternative for workflows in which the default
thumbnail resolution is sufficient for low-rated images.
245Chapter 6 Displaying Images in the Viewer