couple of more tips may be appropriate then, - Be sure to set the Bacground Prop to not Cast Shadows in its properties box (Ctl-I) to keep it from blocking your lights. - If you are using a distant background image, and don't want your scene's lights to affect that image, then set the background prop's Object & Highlight Colors to 0% Black and the Ambient Color to 100% White. That'll keep your background image at full brightness consistantly (without overexposing if it gets hit by a light).