fitting photos on screen in slide show

If you want the photos to fit the screen exactly you'll have to crop them to the same size ratio as the monitor. With the scale option portrait photos will always be cropped top and bottom. To see the full photo you need to not use the scale option.

Do you Twango?

TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've written an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. It's compatible with iPhoto 08 libraries. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

Why is it that when you crop a photo in a slide show that is is cropped that way repectively in all other formats the photo is used in like a book for example?

I is there any way to scale a photo one way for a slideshow and crop it another way for a book?

The Slideshow Settings option says Scale Photos to Fill Screen, not Fit Screen.

So your photos will be zoomed and cropped so that all screen pixels are filled.