If I may jump in with some explanations... HDRI means High Density Range Image. As opposed to the ordinary 8-bit images (JPEG, BMP, PNG etc.) and as opposed to 16-bit images (TIFF, PNG), it actually has 32 bits per channel. So, ordinary images you see around are actually 24-bit, the so-called 16-bit images are 48-bit, while HDRIs is 96 bits. (I'm not going here into the representation of HDR data with less bits.) You don't need HDRShop to create HDRs. You can use Photomatix, for instance. Or even Photoshop CS2. (Although there's a way to fake HDRIs in Photoshop, too.) The process of combining different JPG or TIFF photos into a HDR has to be started in the camera. You shoot the photos at 1 EV stop apart. Then you combine them in an appropriate program which will merge all the different light data into one image - HDR - with the dynamic range unachievable in photos by ordinary means. Then, to use a HDRI in 3D, you usually need a panorama. The easiest way to create a panorama is in programs like Realviz Stitcher. Shoot the photos that will go into a panorama at... three, let's say, diferent levels of exposure, at least 1 EV apart. Combine each level of exposure into a spherical panorama and bring all the different panoramas into the program of your choice to combine them into a HDR panorama. Where HDRShop comes exclusively into play is that only it can create angular map HDR images, or angular map light probes. Bryce recognizes only that format and no other HDR program can output angular map light probes. I certainly hope the first fact will change soon and Bryce will be able to recognize ordinary spherical panoramas or the cross format or what not. Hope this helps.

-- erlik