Background Video is shown in Rendered mode but not when szene is rendered i have a 3D Object and want to add a background image( if possible even a movie) to this 3D Object. I use Cycles to render and tried a plane with the 
image as texture. When i go into render mode, it looks like this(picture with background) and when rendered, it has no background. The key also looks into 
a different direction.

Should i even use Cycles for this or use motion tracking? i tried to use that but had several problems. 

http://imgur.com/a/Wk1VN

Rendered mode


When scene is rendered
Try any of these node setups in the compositor:

Movie as background:



Image as background:



Source:
cycles not rendering movie clip used as background