Quote - Not sure what a 'shadow camera' is.  Using Firefly with auto settings.  None of the 'Option' boxes on FireFly are checked.

However, I get a very good render of a very small area.

The problem is restricted to the scene.  Opened another scene and it render fine.

The shadow cam camera is a camera that in effect lets you look at what a light is
looking at.  Each light has a shadow cam associated with it.  In the camera select
they will be at the bottom of the list of cameras with a name like Shadow Cam Lite 1,
Shadow Cam Lite 2, etc.  They are useful in making sure your light is pointing at what
you want it to point at because as you move the light, the camera view follows the
light movement. So say you want to see where light 2 is pointing.  You select
Shadow Cam Lite 2.  If you don't see anything in the camera, your light isn't
pointing at anything, so you would rotate the light 2 x,y,z until the object you want
the light to point at comes into the view of your shadow light camera.