Apple Aperture - Manual (Page 160)

160 Part II Photo Editing
Selecting Image Preview Options
Aperture can create high-resolution JPEG images that are shown when you select an
image in the Browser. These preview images allow you to quickly see and work with
your images when you select them, even if images are offline referenced images. The
previews allow you to display high-resolution, detailed views of images in quick
succession in the Viewer and when displaying slideshows using the best quality of
display. You can also share the preview images with other applications. You can select
preview options in the Preferences window that allow you to control the creation and
quality of the previews.
You can have Aperture create high-resolution previews of your images automatically, or
you can control the creation of previews manually. You can have Aperture create
previews for each new project that you create. You can also have Aperture create
previews for all your projects or for only specific projects. For example, you can select a
project and specify that the images in it should have previews created for them. You
can also specify that other projects don’t create previews for their images. You can
control the creation of previews on a project-by-project basis. Aperture creates
previews for projects as a background task that you can monitor with the Task list.
You can also control the creation of previews manually. You can select versions and have
Aperture create previews for them when needed. Thus, when projects are not set to
create automatic previews, you can still create previews for specific versions as you want.
You can also change the quality of the preview images to match your working
preferences. For example, if you don’t require high-resolution previews, and prefer to
work with images that are smaller files, you can lower the preview image quality. This is
particularly useful when working on a MacBook or MacBook Pro.