Ah ok.
Yeah, the frame buffer is set to 32-bit floating.
Not sure where to make the change in PhotoShop to save it as a 8/16-bit file format. I've looked and looked.
Thanks for the replies guys...
PS: If there isn't a huge hit/penalty on render times, I think it would be silly NOT to render all my final renders as 32-bit and do some post in PS and save a 8/16-bit version. So many more options...