… Can you help me figure out why "picture in picture" is not droping the effect in as transparent?
the PiP doesn't support color-key.
if you want it transparent, the inserted clip has to be proRes4444 encoded (only video codec supporting alpha-keys), but I never tried, wether iM supports this 'pro'-codec ...
here a very quick'n dirty test:
a Motion5 ready-made animation, exported as proRes4444
inserted into iM11 as PiP
so, THIS way, it works
… So are you telling me to go to the Motion5 site and download one of their pre-keyed effects? …
I said, the the PiP of iM does not support green-screen - you asked for in your initial request.
what I said, after a test: if the PiP-movie contains alpha-keys/is encoded as proRes4444, then iMovie shows transparencies. to create such a test-file, I used one of my other toys, Motion5. Which can be used as 'effects machine' for iMovie - but has a very steem learning curve/professional tool!
… and I have no idea, where on http://www.apple.com/finalcutpro/motion/ you get the info ....
… I went to the site and saw that I would need to pay for each one …
back to your original question:
What do you like to accomplish, in plain words?
Karsten mentioned that Motion has a steep learning curve. I hesitate to jump in here, because I have not gone up that learning curve yet. But let me make some assertions that you can take with a grain of salt, or maybe Karsten can confirm or deny.
1) Motion does indeed have advanced compositing and keying capabilities, although probably more people use it for motion graphics. And after removing a key, you could export in ProRes 4444. (I did not know Motion had this capability of keying and compositing. I had to look it up in the manual).
2) However, the ProRes 4444 does not automatically come with Motion. It comes with Final Cut Pro X, so you would need to purchase that as well.
3) If you own Final Cut Pro, you could probably use your pre-keyed effects without the constraints of iMovie. You could place them, mask them, keyframe them, etc. You could do this whether you have Motion or not.
Yours very tentatively (because I don't have first hand experience).