I'm not sure what's going on here. I'm puzzled that the sphere and plane are so dark and yet the background so light. Have you tried roating the camera so that a different area of the map is shown? If there are large areas of shadow in the Terragen file it will obviously affect things. It may also be helpful to reduce or increase the brightness for Terragen maps, either in HDRShop or by using the Itensity slider in C3. Sorry not to be more help. I'm new to this too! Mark