Can you paint your wall a green screen color and still use green screen software?

Answer 1

A painted green wall can be used very effectively with chroma keying (the technique used to isolate a subject from a colored background). There are some things to keep in mind before doing this.

First, wives and girlfriends generally do not approve of such color schemes. Chroma keying and elegant color schemes rarely mix.

Assuming that the first issue can be overcome, the final choice of paint may be the result of experimentation. Be prepared to try several different paints on a small scale first. Most chroma keyers allow the background color to be tuned to suit the backdrop and it is well worth spending time getting the set up right.

Lighting is important. Keep the whole background evenly illuminated and make sure that the subject does not cast shadows on the background. Some chroma keyers can use shadows on the background to provide a shadow on the final background image but for most purposes, avoid shadows - they just make the keying more difficult.

The green background will also illuminate the back and sides of the subject, causing unwanted effects such as a green cast to the sides of the subject. Keep as much distance as possible between the screen and the subject. It's worth experimenting with some backlights of a complementary color to help to overcome the green fringe that is sometimes seen. Shades of pink are a good starting point.

Green is not the only color that can be used. Blue is often used and causes less a less noticeable fringe effect but does not work well with blue clothing.

Finally, the wall does not actually have to be any specific color. Using a white wall and lighting with green or blue gels will create the same effect. The gels need to be strong, primary colors and used with high power lighting. This technique demands distance between the subject and the background to avoid white subject lighting spilling onto the background. Given sufficient space and controllable light fittings, this technique can work well without having to live with a green wall.

Chroma keying can be used very effectively and opens the door to a huge variety of effects but remember that it is not an easy technique to master. This is proved far too often in low budget news and tv programs where insufficient time, lighting or space is assigned to the effect. Separating the subject from the background is relatively easy. Making the end result look natural is far harder. Spend time to experiment and find out the schemes that work best for your own application. The time will be a great investment and will pave the way for some great results.