Although I don't use iPhoto for managing my digital images, I wanted to be able to watch slideshows using Front Row on a Mac mini connected to a projector. I created a Folder Action Script to pick up a folder of images from a hot folder, and then import those images to an iPhoto album with the same name as the folder.
The problem was that the slideshow settings had to be adjusted for each album individually. I tried changing the settings for the library. That saved the music settings, but other options like slide duration, looping, and the Ken Burns effect weren't applied to new albums. I assumed that the settings would be stored in a .plist file. The file is com.apple.iPhoto.plist in the ~/Library » Preferences folder. I used the following commands from Terminal to set the slide duration to four seconds, disable the Ken Burns effect, and disable looping:
$ defaults write com.apple.iPhoto SlideDuration -int 4
$ defaults write com.apple.iPhoto SlideShowAutoPanAndZoom -string NO
$ defaults write com.apple.iPhoto LoopSlides -string NO
Note that this will only affect new albums. Settings for existing albums are stored in the AlbumData.xml file in your iPhoto library folder.
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