Of course, Arnie is right. Motion is really good for this job once you get the workflow down.
To answer your question, the velocity “handle” is really only a small purple dot that is located directly on the bezier handle. You slide it up or down to accelerate or ease. It’s very sensitive, but if you zoom way in on the Canvas, you’ll gain more control. Looping in QuickView (which no one probably does), will allow you to see the result of your tweaks. If you’ve never seen it demo’d, you’d never really even know this thing exists. Unless, of course, you read the manual. But who does that? 😉
So, you see–it takes extra care to finesse the motion controls in FCP, but it can be done satisfactorily. Especially if you extend the Center keyframes beyond the trim points of the clips, then dissolve through the move. Whether you want to spend that time to do is properly is up to you.
However, as Arnie points out, Motion is the app to use for full control of position and scale. After Effects can take is one step further with the addition of a simulated 3D environment with 3D cameras and 3D lights. Boris RED which plugs into FCP does a bang up job along these lines as well, but you can extrude the edges of the photos for an added effect very easily.
Lately, these kinds of projects are so commonplace that I am getting sorta lazy with requests to do this kinda thing for family and friends. For that, I just toss my photos into iPhoto 5 and it actually does the rostrum moves to music automatically. It’s pretty cool. iMovie is also a no brainer way to get the job done down and dirty. The down side is no real control over position, scale or anchor point.
Good Luck
Kevin Monahan
Author – Motion Graphics and Effects in Final Cut Pro
fcpworld.com