Add shadows to existing images and video

[Baruch]

Hi,
I have a few images of scenery and some videos of scenery. I want to place few objects into them. How can I add shadows to the image and video for these added objects?
Thanks.

[CADTomato]

Hi,
First you have to match the scene of camera to your footage then create objects where the actual objects in your footage are only the ones that you need to apply shadows and in your material editor use a matte/shadow material on the objects that will receive shadows.