3.4

Chapter 5 Displaying Photos in the Viewer 123
3 In the Library inspector, select all the projects, then choose Maintain Previews For Projects from
the Library Action pop-up menu (with a gear icon), so there is no checkmark next to it.
This turns o automatic preview maintenance for your existing projects.
Note: You need to perform steps 1 through 3 for each of your libraries.
4 If you have already generated previews for some projects and do not want them, select all the
projects in the Library inspector, then choose Photos > Delete Previews for Items.
This deletes all previews that have been generated previously. You need to do this for each
library in which you have already generated previews.
Sample Workows for Using Previews Eectively
There are several methods for using preview images eciently and eectively:
•
Generate previews for projects you intend to keep oine: A JPEG preview is displayed when a
referenced image’s original is oine or cannot be found. This makes previews a great way of
maintaining high picture quality while conserving the disk space that originals (especially RAW
les) 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 oine (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 workows in which the default thumbnail
resolution is sucient for low-rated photos. For more information about searching for photos,
see An Overview of Searching on page 229.
•
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 An Overview of Smart Albums on
page 255.
To use previews for oine referenced images
1 Make sure the external hard disk containing the referenced originals you want to keep oine is
connected to your computer.
If the originals you want to keep oine 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 oine,
choosing File > Relocate Originals, selecting an external hard disk location for the originals, and
then clicking Relocate Originals.
2 Select the project containing the photos whose originals you want to keep oine, then choose
Photos > Update Previews.
3 When the previews are built (you can check the status by choosing Window > Show Activity),
you can disconnect the hard disk containing the originals.