Wow, that helped! I had no idea there was such an option. There is no big jump in lighting now. On a related note, however, I'm still trying to lighten the overall effect in the room during the walkthrough recording. As you can see in the screen grab, the Full camera view on the left is bright (I increased Ambient Light setting to do this) and yet the recording I just made (shown on right) still remains dark. Before I changed the Wall option box to "no room definition," the kitchen side of the room was nice and bright as you can see in the original video. How do I keep it that bright? Very strange.... Thank you for all your help!!