Superimposition in video editing refers to combining two or more pieces footage together to create a single video. This means overlaying the first video on top of another video, then allowing both to be seen on the same frame by altering their opacity. This allows the combined footage to appear together on-screen at the same time. This is similar to putting one stained glass on top of another. Both have translucent properties, and placing one on top of the other alters the look.
Open your preferred video-editing program for the process. Use the native program in your computer such as the PC-based Windows Movie Maker or the Mac-based iMovie, or use any of the other popular video-editing programs such as Adobe Premiere Pro, Final Cut Pro or Sony Vegas.
Make a "New Project" in your selected video-editing program, then import the videos you want to superimpose. The "Import" button is usually seen under the program's "File" menu, which is located on top of the screen. Your imported videos will appear on the project's "Import" or "Video Clip" window.
Drag your first video onto your work area's "Editing Timeline" and place it on the timeline's "Video Track 1." Drag the thin vertical line located within the timeline on any part of the video clip. This allows you to view the exact part of the clip where the vertical line is located using the "Preview Monitor." To play the footage, press your program's "Play" button. Most programs also allow pressing the keyboard's space bar to initiate playback or stop the playback of the video in the timeline.
Drag your second video onto the timeline and place it on "Video Track 2." This makes the second video the default video that can be seen on the "Preview Monitor" because the video track on top makes the video clip placed on it the default video viewable on the "Preview Monitor."
Highlight the first and second video clips located on the first two video tracks in your timeline. Use the "Composite" or "Superimpose" function in your editing program so that the videos will be processed for the superimposition effect. Change the visibility of each clip depending on your program's available superimposition effect options. Use the "Preview Monitor" to see if your superimposed videos achieved your intended look. As an alternative, individually alter the "Opacity" of each video clip to make it translucent. In video editing, if you make each video clip's opacity 50 per cent, this means that both video clips will be superimposed on each other and allow you to view both shots on a single frame with 50 per cent transparency for each clip.
Render your superimposed videos by clicking the "Render" button located in your program's menu options. This button is usually under the "Sequence," "Video" or "Effects" menu. The rendering process allows you to generate the final footage based on the superimposed effects you made in your video clips.
Export your edited video to your desired video file format like MP4, MOV, WMV or AVI. These are popular formats that are usually compatible for playback of your video in a media-playing device or a multimedia software program. These are also the formats typically used when burning your movie onto a DVD.
Always save your project after making any significant change in your edit to avoid the risk of losing the prior edits you made. Most programs use shortcut buttons for saving or rendering your video. The "Save" shortcut command usually requires pressing "CTRL-S" in Windows or "Apple-S" in Mac. The "Render" shortcut command usually requires pressing "CTRL-R" in Windows or "Apple-R" in Mac.