Premiere - Green Screening

After we had covered all of the mandatory requirements for the assignment we began to look at advanced features which you can use in Premiere. This is were Jamie taught us Green Screening. The more technical name for green screening is Chroma Keying. It is the act of layering to pieces of video footage together. Green screening is most commonly used in films and the weather forecast as these are areas were the background needs to be changed. The main idea behind green screening is filming a shot in front of what is known as a Green Screen and then importing this into a Premiere project in order to change the green screen into a separate clip. So within the lecture we took footage in front of a green wall as this was the nearest we had to a green screen. This was then uploaded and imported into a Premiere project.

So what did we do next? With it imported into Premiere I then found a background scene from YouTube, downloaded this and then also imported this into Premiere. The scenery clip was then added to V1 while the footage was placed on V2. I then added the Ultra Key video effect which can be found within the Keying folder of Video Effects. The next stage was to set the Key Colour. This is the area we want to replace and hence the key colour needed to be green. Although you could search for a green which is similar to the screen I simply used the eye dropper tool to select the green background, this was more accurate than selecting a default green. Now the second clip could be seen in the background. This was however a different size to the screen itself and hence I needed to now resize this. To resize the background I simply double clipped on the footage and then was able to resize the clip. Due to the fact that my recorded footage wasn't directly centred on the green screen I had some white edges showing at various points in my combined clip. To remove these I was able to use the Eight Point Garbage Matte. These garbage mattes allow you to adjust the size of the green screen to remove any 'garbage' which was added into the clip accidently. There are three different types of garbage mattes. These are 4 point, 8 point and 16 point. The difference between these are the number of editable points and hence the 16 point garbage matte has the most editable points. This would give the least noticeable changes as the points are so close together. The screenshots below show each of these garbage mattes.

4 Point:

8 Point:

16 point:

With my clip now looking a lot better I decided to add some effects in order to blend them together better. I added a brightness and contrast effect. The settings I used can be seen below. These settings darkened the footage of James to blend in better with the darkness of the background.

I then looked at stabilising the clip in order to perfect it. To do this I used the Warp Stabilizer which can be found in the Distort folder. I was able to set the smoothness and then start the stabilization. This was a time consuming aspect but it made a big difference and both clips looked a lot smoother and seemed to blend better.

The video below shows all of these techniques in practise.

 

It is clear that this video clip is not to the best quality however the concept is definitely there. Of course if I was to include this idea into my final DVD Trailer I would take more time and consideration however for the simply experimenting purpose I feel this is fine.

Green Screening is not something which I aim to use in my final DVD Trailer as I don't feel that I could film anything as high quality or realistic as the clips which I have already found however being able to use and understand this technique is a good skill to have and hence I feel this was time well spent.