Yes, that Greg Ward software looks good. Thanks for the link. It says to take multiple shots of a scene, from severely under-exposed (no white pixels) to severely over-exposed (no black pixels), which it then combines somehow into an HDR image. The software apparently produces a 32-bit or 33-bit image. When I used the HDRI browser (Photosphere) to open an EXR image (ILM format), it was able to open it, recognize it as EXR, and said it was a 48-bit image. This leads me to believe that: 1. Carrara may be able to use EXR images. 2. EXR images have "smoother" dynamic range than HDR images.