Hi there
You need to add CAMCORDER or CAMERA (depending on Beo4) to the list key.
This is done by holding standby (the red dot), and pressing LIST.
You should see ADD? appear on the screen. Click GO, then scroll through the list using the LIST key (or up/down depending on Beo4) until you see either of the above. Add using GO then press EXIT to exit out of the set-up menu.
Now when you scroll through LIST you should see it as an option and be able to press GO to select the input.
It won't affect your uncle's normal operation so no need to worry about that.
Hope this helps!