I want to add a black and white as well as a film grain effect to the same video in iMovie 10. I can't see any way to do this as applying one effect removes the other. Does anyone know how to do this? Thanks.
Not in iMovie 10.0.5, unless you open up a separate project, drag the clip in there, apply the 1st effect, export it, then drag the exported clip it into your main project or 2nd project (if 3 effects or more effects are needed), then add a second (or final effect).