The Ken Burns effect adds motion to still photo slideshows by zooming and panning each photo as it is shown. This movement adds interest to the slideshow and can also be used to highlight certain parts of a photo.
The problem with using the Ken Burns effect in prior versions of iPhoto was that the slide show would sometimes cut off the heads of the people in the photo. iPhoto '09 tries to solve that problem by using its facial recognize technology. In theory at least, iPhoto will recognize the faces in the photo and not cut them off when performing the Ken Burns effect.
I say "in theory" because iPhoto doesn't always get it's facial recognition exactly right. Therefore, some tweaking of the Ken Burns effect may still be necessary.
One big change that iPhoto made to slideshows is the introduction of Themes. The first two Themes are "Classic" which fills the screen with static images, and "Ken Burns" which adds the Ken Burns effect to every photo. You can still tweak the Ken Burns effect on an individual photo basis.
To adjust the Ken Burns effect for individual photos in a slideshow:
- Select the photo you want to adjust.
- Click the Settings button (looks like a gear) under the photo.
- Click "This Slide" at the top of the bezel that appears.
- First you are going to set the Start point for the KB effect. Use the Zoom slider at the bottom right of the iPhoto window to zoom in and out of the photo. Then move the mouse pointer over the image. The mouse pointer changes to a hand. Click and hold the mouse button and pan around the photo around to the desired location. This combination of Zoom and Pan sets the Start Point.
- Now set the End point of the KB effect. At the bottom of the bezel is a switch that says Start and End. Click on the End side. Now do the same Zoom and Pan technique as described above. When you are finished, you have set the End Point.