Set duration of still frames

Hi,

I want to do a film out of 110 still frames (pictures) for a birthday party.

I am using iMovie 10.0.7 and working in a template (photo album template, to be exact).

So, i already have my pictures imported, tweaked a little with Ken Burns and i do like the transitions.

BUT. I want each still frame to be shown longer. Right now, iMovie seems to decide for itself how long one picture is shown.

I want to set a standard duration for the still frames, so that each picture in the movie is shown for eg. 10 seconds. Then transition to next picture.

Does anybody know how to set this?

Thanksalot.

Guitardude