Green screen (ChromaKey) Compositing

October 14, 2019  •  Leave a Comment

Green Screen Compositing

Many photographers and movie makers are familiar with green screen images. The foreground is typically the actor, whereas the background can be practically anything that anyone can imagine. In some cases, the background can be placed in order to save time and money while other times the background can be pure fantasy such as when Superman flies through the air.

Green screen need not be limited only to background images. As seen above, the model is sitting on a stool covered by green fabric, and in the final image not only has the background color been changed, but the model is sitting on a giant mug. Could the mug have been fabricated, almost certainly but the materials, time, and possible expense of such as project may have been prohibitive. 

In our world at least, dragons do not exist.  Puppet forms can be created out of green fabric, filled with stuffing, and the actor can then physically interact with the puppet during the project. In a fantasy project the actor may be working with puppets in different positions throughout the project.  Puppets (or props) need not be from a fantasy world for that matter. They could just as easily be an animal such as a wolf that may be difficult to bring on set, or it could be a very large machine that the actor may need to operate.

Green fabric suits, headpieces, gloves are readily available from costume stores. When photographed against a green background, everything disappears that happens to be green. Think of the possibilities such as levitation of props or even actors during a production.

Of course, some if not all of this is possible though the use of methods other that green screen processing. With dedicated software or specifically selecting out green as in Photoshop, the process flows a little smoother and can be less time consuming. This blog post is really not to teach green screen, although I have shot quite a few projects using this process. There are volumes of information in books and videos that go though each step of the process in great detail.  Some important points that one will find with most knowledgeable sources include:

  • Avoid folds, creases, and shadows on your background
  • Even light across your background
  • Keep your subject at least 6-8 feet from the background to avoid a green cast
  • Light your subject separately from the background
  • Use a longer lens (at least 100mm) for compression

Photoshop is great for so many things, and of course you can use this software to remove the green props or background. Dedicated Chromakey software can make you life a little easier if you choose to work with green screen photography on a regular basis. As a side note here, "Blue Screen" photography is just another version of the same process.

If you would like to try Chromakey (Green/blue screen) photography, the following link Green Screen  will get you started for a relatively low entry price. They kit provides the fabric as well as software so that you may give it a try.  For slightly more this kit Savage Green Screen  will also include a variety of backgrounds.

** Images shown above were taken from Pinterest for illustration purposes only**

-Bob Barford is a published photographer based on Southern PA.


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