LPR001 posted at 9:59AM Wed, 20 July 2016 - #4276192

Backdrop you can either add to a plane which I use if I wish to get the scale right like if I have characters inside house and want the windows overlooking the backyard. i find this my preference because i can move it back and forth to get it looking right. You add the image in the Surface Pane > Diffuse and depending on shape of image you will probably need to tweak the scale sizes to suit. the second option is to add it as background Environment Pane > Backdrop > Background you will see the top option which color adjustment but a little drop arrow click that and hit browse to choose the image. I use the second option as well but it kind of dictates my camera angle a little too much for my liking. it just depends on what you have in mind for your set.

That works. If your background image matches the aspect ratio of the render you can also use a backplate. (Backdrop under the Environment pane) or use an HDR/EXR file as your backdrop by turning on Draw Dome, under the Environment section of the Render Settings pane.

Note with the last choice your lighting will match your background, if that is important for your render.