Using green screen in iMovie

Object is isolated in front of green screen

Today, i investigated the possible filming and production skills which i might use, such as the green screen effect, which as years gone past has been made very simple and easy. In my story, the wife drowns in the river on a day lovely day out with her husband. 

Now since its 2°C at the start of January and making a character submerge into cold water to give the effect of a drowning can be quite difficult. I therefore used the advance of technology to help me. Since i will use iMovie for the basic editing, i decided to perform some research on YouTube and other websites so i could learn the basic techniques required for a green screen effect. I began to see how easily this could be performed with great effect.

Background is chosen to replace green screen

Firstly, an object (in my case, the wife) has to be placed in-front of a relatively large green screen. I record my wife lying down for the effect of drowning and her head beginning to submerge under the water. The wife's hair could be wet to start with so when the water is added as the background, the effect will be more realistic.

Secondly, i would need to place a suitable background to replace the green screen. As a photograph would not work, i would have to record the flow of the river from the bank where, theoretically, the wife would be. I would import the clips from the camera through the camera USB into iMovie.

The two put together...

Thirdly, i would drag my clip of the green screen over the clip of the river. iMovie then gives me the option to choose 'green screen effect' which when clicked it, the flow of the river should replace the green screen. Furthermore, i would need to check the timings of both clips and make sure they work together accordingly. Further video adjustments and editing can be made once the green screen effect is up and running.