best way is to go to the film veiwer then hit full screen, position the camera as you wish (press F1 then F8 to move your "camera" freely) with the arrow keys, Page Up, Page Down, and the numpad for the camera angle.
Then press "Print Screen", open Paint or some other image editing program you have and "paste" (Ctrl V)
Voila, now you can mess with the image to make it prettier and then save it.