Following on from my post about a filmmaking project involving green screen, or chromakey, I thought I would put together a few simple steps on how to achieve an effect. We are fortunate to have MacBook Airs, which I think are great for speeding up workflow (with AirDrop) and they come with iMovie pre-installed. This is a fantastic application which makes it very simple to produce a high quality output. Green screening is built in too!
1. Create a ‘Movie’ Project
Trailers are great too, but not for our purpose.
2. Select an appropriate scene for your project
There are loads of different themes included in iMovie which can be really useful in the classroom. These feature different theme music, transitions and titles.
3. Give your project a title
4. Drag your background image or video into the timeline
Always start by adding your background ‘layer’. I have chosen a still image downloaded from Pixabay.com which hosts thousands of high quality, open source images.
5. Crop/Adjust your Background
By default, iMovie adds ‘Ken Burns’ effects to still images. This gives a great effect as it slowly pans and zooms on the photo. As a background for a green screen movie, this is not needed.
6. Add your top ‘green’ layer
You should now add the recording you have made with a green screen background. For this tutorial I downloaded stock video footage from stockfootageplus.blogspot.com of a flock of birds flying. Make sure your ‘green’ layer is on top of your background.
7. Select Green/Blue Screen from Video Overlay Options
After clicking on the green screen section of your timeline, ‘Video Overlay Options’ appears. Click on this and select ‘Green/Blue Screen’. Watch the magic happen!
8. Tweak your effects and customise your movie
Use the ‘clean-up’ tools to make sure you have a good quality chromakey. For this example, the birds were too close in colour to the salt flats so the overall effect isn’t great. It is super fast and simple to create these effects however so I encourage you to try it.
Here is the final output of my tutorial on youtube. All in all, this took 10 minutes (including taking screen shots along the way!) Give it a go, post any links to youtube projects in the comments!
I managed great results in class with a make shift green screen made by sticking green card to the wall; filming on iPad Airs, with no lighting and no additional microphones. I look forward to investing in some more filmmaking gear to see how far we can take it!