http://www.bit-tech.net/gaming/2005/09/21/lost_coast_benchmark/1.html
With the articles explaining HDR in two places …
http://www.bit-tech.net/gaming/2005/06/14/hl2_hdr_overview/1.html
and
http://www.bit-tech.net/gaming/2005/06/14/hl2_hdr_overview/1.html
Wow.
Yeah… I have been looking at the videos, trying to find telltale banding artifacts to figure out which color space compression they use…
Nice with an article about it, though…
EDIT: Just read it and still no info on the colorspace stuff they do. If you guys find any tech info, please post a link for me 
Well I have some tech-stuff but not all is related to HDR though, and I don’t really know if they are helpfull at all, but I though I give it a shot
About realtime Radiance (Very technical so you might like it) :
A paper on Hdr from Paul Debevec’s page (you might have seen this since this is siggraph stuff:)
And an article I recently found on Hdr encoding (though not realtime but more in general:)
http://www.anyhere.com/gward/hdrenc/hdr_encodings.html
And another Realtime lighting paper:
http://graphics.ucsd.edu/papers/plrt/
Hope at least you find some new possibly usefull information there, but Im afraid if I don’t know enough about anything to help you out here…
Good luck on the HDR implementation!
Liked stuff on realtme PRT… Seemed very interesting (albeit pretty far away)…
I’m not far at all in the HDR stuff… Basically trying to find something that will work on any radeon9500+ or GeforceFX. So far, most things seem to be running with floating-point textures.
That’s what so interesting about the HL2 approach - they supposedly managed to squeeze it in in using only normal RGBA encoding.