Steve, it's impossible to use hdr images in Poser. Poser won't accept the .hdr image format for a start and its somewhat rudimentary render engine is totally incapable of doing any radiosity calculations. You'll need software that can specifically calculate these types of solutions - LightWave, Max, Maya et al, Carrara and Vue now as well, apparently. There is a poor man's hdri setup available at er, RDNA I think? that attempts to simulate this type of thing, but it's still a fake. I'm not sure I understand that question ockham :)