Green Screen Tutorial

After posting about how I make movies with my kindergarteners, I had some people ask about how I use the green screen. So, I thought I would write a tutorial for you.  It is super easy to use. 
  This is how I use my green screen.  It is probably not the only way you could use it, but this is how I do it.  I am not a professional.  I have played around with it and it seems to work for me and my classroom movies.  I hope this tutorial inspires you to use a green screen in your classroom. 

First you need a green screen.

 I originally purchased Kelly Green fabric from JoAnn's.  The fabric worked very well for a green screen.  You could also buy a professional green screen or use green butcher paper.  In the picture above, I used green butcher paper.

Any part that is green will be covered by the picture I place on it.  If you notice my set up in the picture, the calendar is to the right of the green.  If the video camera would have gotten the blue calendar on it, the calendar would be seen on the video.  Also, when using a green screen, if you are having a student in front of it they can't wear green or they would be invisible.  I have also had a problem with gold.  I guess gold is too much like green so it doesn't work very well.

Once you have a green screen, you will need extra light.  The more light you have, the better, but you don't want too many shadows.  I had a parent buy me the construction lights.  I put one on each side.  I would like to get another one to have in the middle.  I usually put them on a stack of something so they are off the ground.  You could also buy a stand for them to get them higher.  

So now you have a green screen and it is well lit.  Now double check and make sure the green screen doesn't have any deep wrinkles.  Sometimes the wrinkles will show up on the movie.

Now you are ready to film what you want in front of the green screen.  Once you have all of your film, open up iMovie.

iMovie- Screen when you open it.

Click File, then click New Project.
 
 
Select the theme you want your movie to have.  Give it a name and then click Create!

Next you need to put what you want as the background in the top box.  I had the picture on my desktop so I dragged it to the box to put it into iMovie.  You could click the T on the right hand side to add pictures from iPhoto if that is where your picture is.  You could also use a stock video as your background.



 
Next you are going to click File.  Then you need to import your video clips.  You can import from your camera or you can import from movies.  Where you keep your video clips is where you will import them from.

Once you import your clip, they will show up in the bottom box. 




Next you need to click the clip you want to use.  The clip I want to use is highlight in yellow.

Once you click the clip it will say how long the clip it.  (Mine says it is 15:07 seconds long) 

  Then I go up to the background I added and see how long it is.  Once I click the background it will be highlighted and say how long. (Mine says 4:00 seconds long)  As you can see, my background is too short.  I need to make it the same length as my video clip. 

  Click the wheel under the length.  Then click Clip Adjustments.


 
This is what opens.  Then change the Duration to the time of the video clip.




 Here my time is changed to 15:07 seconds just like the clip.  Then click Done.



 
Once you click done the background will be the same length as the video clip.

Now click your video clip.  Mine is highlighted by yellow.
 

 
Then drag your clip up to the background you chose.  Go to the spot you want to add the video.  Once you unclick the video a window will open.  Go down to Green Screen and click that.

Then you should see your video clip added to the top of the background.  Then on the right side it should be put together so you can view it.  This is how it would really look.  If you are not happy with how it looks there may be a way to fix it.




 
Click the setting button on the background.  Then click Video Adjustments.

 In this picture I played with the Exposure.  This one has 25% exposure.  As you can tell, this doesn't make it look better for my video.

Here I played with the Exposure again but moved it the opposite direction.  Adjusting the Exposure, Brightness, Contrast, and/or Saturation may help your video.  Also adjusting the red, green, or blue gain may help. 

 
I think my video looks good without making any adjustments to it.


That is how to use a green screen.  I hope this is helpful!