If you're a VFX artist, or work with video, you most likely know what a green screen is. Basically, it's a back drop that you can use in film and video productions to provide a plain color, so that when you bring the footage in a post-processing software, you can easily replace that back drop with something else. Here, we'll see how to make your own inexpensive green screen setup.
There are three important things to keep in mind about making a green screen set:
* Having a good fabric
* Getting the screen as smooth as possible
* Having good, even lighting.
So to start with, you need a screen. Usually, these are made of fabric, and there are a lot of different models and costs. For a fairly small 9 ft by 15 ft setup, you can pick up a Chromakey Green Muslin Screen on Amazon
for about $35. There are also a lot of other models that you can find around this price, and they all work fine for small budget productions. The main disadvantage you will get with buying a cheaper fabric is that you may have to work a bit more to get the wrinkles out, and the color may fade over time, making it harder to key against it. Otherwise, this type of fabric works fine.
One thing to note is that most of the green screens aren't sold with any sort of attachment or support. You will need to get it up against a wall somehow. The easiest way to do that is to attach supports to a wall, but if you don't have a wall you can use, simply buy a set of supports like the SP2000 Backdrop Background Support Stand which costs around $59. The benefit is that if you ever want to film outdoors, or at another location, you can bring your setup with you. Usually, most of these products come in a way that's easy to carry and easy to setup. Simply follow the instructions and use the spring loaded attaches to bring the bars up to hold your screen.
Once your green screen is set, you need to make sure it's extremely plain and smooth. One trick is to use an iron on the fabric in order to remove any wrinkle. Then, make sure the screen is vertical. You can use a level to make sure it's exactly at 90 degrees. Make sure you place the bright green side of your screen in front, and avoid having that side touch the floor so it doesn't get dirty unnecessarily.
The last step in getting your own green screen set is to have proper lighting. This will make it much easier to key correctly once you're in your post-processing software. The goal is to have the whole screen as bright and as evenly lit as possible. You want no cold or hot spot. A good setup includes 3 lights minimum, with 5 lights being best. If you use tungsten lights, make sure you have tungsten to daylight filters. If you use florescent lights, make sure you remove the diffuser panels in front of them.
With some budget for your lights, one popular choice is FloLight
, which are lights that provide the right color and temperature, can be mounted any way you want, and can be adjusted in many different ways. However, you can easily get a much cheaper setup simply by visiting your local hardware store. You can get long tube fluorescent lights for around $35. One important thing to remember is not to mix cold and hot lights, because they will produce different types of lighting. So don't mix halogen and fluorescent.
Finally, once you have you green screen and your lights, you can start filming. Your resulting green doesn't have to be exactly chroma green
, as long as it's as close as possible. Whether you use Adobe After Effects, Final Cut Pro or another post-processing software, you'll be able to key out the green, and if your setup was well done, you will get a good result, and all of that for less than $100 (minus camera, supports and actors!)