Difference between 48 bit color and 48 bit HDR color files??

[pneaman]

Can someone enlighten me as to what is the difference -- functionally or otherwised -- between 48 bit color and 48 bit HDR color files?

Is there a reason to prefer using one over the other? Can Photoshop CS handle 48 bit HDR color files?

[degrub]

48b HDR files are intended to be uncorrected scan data (all of the adjustments are grayed out), black and white point set, with a gamma applied if desired. 48 bit color can be fully corrected at scan time. THe idea is to get all the basic scanning done at a scanning workstation and then later correct the scan using all of the tools normally available. THis was usefull before PS was capable of handling 48 bit files and in some cases is still preferred over PS because of the tools available.