Ed, very perceptive and very true. I'm not at all sure how I would go about simulating exposure settings in C3, but I'm sure it can be done. Right now I only use one image to set up the shot, so I guess, yes, it would be LDR. For what it's worth, though, it seems to work just fine for what I am looking for. But for specifics, I am VERY sure that by using GI images to create the HDR file (whether HDRI or LDRI) it is a better approximation of natural lighting than just adding in a straight ray trace without GI. Maybe I'm rambling.... ?? Ken