yes, sparky, some recent version(s) of poser can export renders as hdr or exr images, but most recent versions (e.g. poser 8, 9) can use hdri as illumination sources in renders.

p.s. when a jpeg texmap brightness is increased by using an hsv node, it can have the same effect in total range as an hdri, but it introduces a step function into the colour gradients.  hence the brightness is increased for illumination purposes, but the lighting detail (the total information available to FFRender to calculate IDL) is far less than an hdri.