Movie reality:

You may have seen in many movies scenes which actually mesmerise you with the locales,But you still remain assured that the background that appears is not for real.

One such technique which actually hides or morphs the background is a Chroma Key Color Transition technique.In this technique the actors and the required scenes are shot in front of a green or a blue screen.

The choice of a green or a blue screen is made depending on the image to which the background is to be changed.For instance if the background has to be replaced by an image of a sea,it is usually shot in a blue screen.Same applies for a green one.Then using a software tool like a video edit magic,the background is changed.Sounds simple,doesn't it.