iMovie "green screen" feature has serious problems.

Works perfectly for me.

Folks,

I ran into the same issue (I named it "transparent green screen", I hadn't a better name).
I spent about a week to solve this problem, since I needed it to build a marriage slideshow.

The tools & Config:
iMovie 09, iPhoto 09, Adobe After Effects CS4
Mac OS X 10.6.2, MacBook Pro 13" 2.26 Ghz Intel Core 2 Duo, 2 GB RAM

The Solution for the "transparent green screen":
I created a movie in AE, and put a green background into it. It was the pure green color.
When I imported the movie into iMovie I just got the "transparent green screen", not the real effect.
I some cases, by changing the background images, I could get the green screen to work, but it was kind of random. Which made it harder to solve it.
I thought it could be because of AE, some incompatibility. I went to Youtube and downloaded a green screen video (a woman dancing in a green background). I inserted the video into iMovie, and it worked just fine, all the way.
Then I tried to match the green color I was creating digitally with the Youtube video's green color. It didn't work either. The "transparent" effect was there again.
But when I looked at that Youtube video, I noticed that the green color was not pure. Because that green background was made in the real world, it was not pure, there were some shades of green.

Well, I just replicated that into the digital world. Modified my video's digital green background. From pure green to a gradient green, but very subtle, almost imperceptible. Just to replicate the "imperfection from the real world".

That was it. Solved. Maybe iMovie 09 needs that imperfection to work well. Using "pure greens" might confuses it.

Please do your tests. And let me know your results.

Regards and greetings from Brazil.

Art101, the iMovie greenscreen effect is designed to work with camcorders shooting at 25 or 30 frames per second. Try rendering your graphics at 30 frames per second (NTSC) or 25 fps (for PAL), and it should work for you.

I didn't do anything special to make it work nor should you have to. It would be helpful when reporting a problem you described what you did and the exact nature of what's wrong.

You sure you have placed the clips on top of each other in the correct order?

no madness here..
dl your two files, created a NTSC-project, added both, worked like charm:

even the tiny serifs key excellent ..

does even work in my PAL surrounding... (= did forget to switch iM to your standard on first attempt 😉 )

.. so, Plan B)?
check, wether you have an unwanted 'plugin' in your set-up, read advice here:
http://karsten.schluter.googlepages.com/im09losttransparencypatch
(don't get irritated by topic of site.. just check)

art101 wrote:
.. tried clicking the graphic you posted, but it wasn't clickable..

the pic is just a pic.. no link, no hidden special-effects .. 😉

the link is the purple part, starting with 'http:// ' in my previous post ..

art101 wrote:
.. I was hoping to see your version of the Muzundrum tagline video (with functional green screen effect).

no prop, here:
http://www.youtube.com/watch?v=y1BaEcBSw84&hd=1

I'll pull it soon.. pretty sure, the Planetarium-view is not your recording.. 😉

Karsten what did you use to download the original clips from the madness site.

art101 wrote:
Thanks for your reply, AppleMan1958. The original clips were all shot at 30 FPS, in native NTSC. I know the rules.

I used a pure "green screen" color and tried everything I could think of to make it work in iMovie... over and over and over again. It's not a camcorder issue. I repeat: iMovie's "green screen" feature has serious problems.

See: http://www.art101.com/101temp/imovie_madness

Art,
I noticed you switched the tracks from what iMovie expects... It's a bit counter-intuitive in iM, but you put the background track on the main video track first, and then drag-n-drop the green-screen video on top of the main track. I see in your pic that you have it reversed 🙂 I say this is counter-intuitive, as it's difficult to get the edits/timing right with the secondary vid track... Maybe iM10 will fix this!

Green screen does indeed work well within iM 🙂

I've spent good money on similar backgrounds too, I appreciate Karsten may have arrived at a wrong conclusion about your footage, however he has clearly been instrumental in solving an issue which was obviously one of misunderstanding on your part and deserves considerably more respect than the reply he has received.

You had an issue, a fellow user like yourself has given his time to help you resolve it.

Why depart on such a sour note and inexplainable rant.