A multiple exposure , simply put, is the superimposition of two or more images on top of each other . In the days of film, this was achieved by taking one picture and then, without advancing the film strip, taking another picture right on top of it. Today even digital cameras allow you to shoot multiple exposures.
In order to click a double exposure all you have to do is turn the the multiple exposure feature on, and click two or more shots are allowed on your camera.
for A high-key double exposure with a human subject as in our example , the background of your first shot should be as close to with as possible . this can be done by shooting with the sky filling up the background . For the second shot we bumped up the exposure compensation and took a picture of leaves for this image.