Is a green screen needed for backgrounds on iMovie version 10.1.14

I am not sure whether you want the Picture in Picture effect that Rich describes.

From your description of Zoom I assume you want to put your actor in front of a background to make it appear that he or she is somewhere else?

If that is the case, you do need a green or blue screen.

You can buy small ones for about £10 on eBay but you can use almost anything with an even green or blue colour.

Before I bought a "proper" green screen I purchased a very cheap blue bed sheet from the local market!

Hi,

No need for using green screen for backgrounds on iMovie 10.

Instead, use the Picture in Picture feature. The procedure is to put your background clip into the timeline and then place your main clip into the upper timeline above the background clip. Select the main clip in the upper timeline and then click on the overlay icon (the one that looks like overlapping squares) in the tool bar at the upper right of your screen. You will see a selection box appear below and to the left of the overlay icon. Choose Picture in Picture. Then adjust the size of your overlaid picture so that it is smaller than the background clip, and the background clip shows like a frame around the outer edges of the inserted clip.

Here's a help link that explains the steps for using the Picture in Picture feature.

https://help.apple.com/imovie/mac/10.1/#/mova1aaa682b

-- Rich

If I misunderstood your post, and you want to shoot a subject in front of a green background so that you can overly the video onto a different background and make it appear that the subject is in front of something else, then Ian is right that you would need a green screen to do that. Otherwise, you can do the procedure that I mentioned.

-- Rich

You might find this video I made useful. It contains a few things you might not have thought about. At ten minutes it is a bit long, so please accept my apologies.

https://www.youtube.com/watch?v=FGBpJzHNMVE