In most cases, Apple's setting for Automatic Ken Burns Effect will provide a completely acceptable result. However, if you wish to zoom further, change the zoom direction, or even turn on the Ken Burns Effect only for a particular slide, you can do so.
To configure the Ken Burns Effect:
In a saved slideshow, select the Ken Burns Effect checkbox.
Click the Start end of the toggle switch.
Using the size slider, zoom to the size at which you want the photo to appear first (Figure 5.11).
Figure 5.11. For my starting point on this slide, I've zoomed slightly so you can see both Tristan and my grandmother Helen in the frame.
Drag the photo in the display pane so the starting view is showing.
Click the End side of the toggle switch.
Using the size slider, zoom to the size at which you want the photo to fade out.
Drag the photo in the display pane so the appropriate part is showing (Figure 5.12).
Figure 5.12. For the ending point, I zoomed in about a third of the way and panned so the frame focuses on Tristan's face.
Click the Preview button to see if your settings work as desired.
Select the next photo and repeat steps 19.
Increase the slide duration to slow down the Ken Burns Effect, and decrease the slide duration to speed up the Ken Burns Effect.
Think carefully about whether it makes more sense to zoom in on the photo or to zoom out of the photo, given each particular picture.
Manual Configuration Necessary for Exported QuickTime Movies
The Automatic Ken Burns Effect generally works very well, but note that it is random, which means that it won't necessarily be the same on any two playings of the same slideshow. As a result, if you're particular about the final slideshow, and particularly if you're saving the slideshow as a QuickTime movie, you should set the Ken Burns Effect manually for each slide. Otherwise, you simply won't know how it will work on any given playing of the slideshow.