Setting duration for multiple photos at once using imovie 11 on the iPad 4th gen.

I am making a slideshow using iMovie on my iPad. I have over 300 photos that I imported and I wanted to know if there is a way to make all the photos a certain duration (ie. 3 seconds). I know I can do this one by one but that will take forever so is there some way to set a duration for ALL of my photos at the same time?