How to Snap a Cool Photo with iSight and Photo Booth
(Optional) Click the Effects button to choose an effect you’d like to apply to your image.
Photo Booth displays thumbnail images so that you can see how each effect changes the photo. To return the display to normal without choosing an effect, click the Normal thumbnail, which appears in the center.
Of course, you can always launch your favorite image editor afterward to use a filter or effect on a photo.