Ok, I figured out a way around the 8 bit problem. I will write a tutorial as soon as I find the time, but that are the basic steps: Open the 16 bit tiff in Photoshop and save in RAW fromat, ignoring all warnings. Open the RAW file. In the dialog that appears tell photoshop that it has two interlaced bit channels. You have now a file with two channels, one containing the lower and one the upper 8 bits. Add one empty channel and change the mode into RGB. Save as this file. In Poser load this file in a Image node. Plug this node in 2 component nodes, setting the component in first node to 0 and in second to 1. With math nodes divide the second node with 256 and add that the first. Subtract 0,5 from the Sum (because Zbrush uses 50% gray as neutral and Poser uses 0). Plug that in displacement.

The jaggies still there are caused by the fact that I did my Zbrush model at a bit low resolution: Only 450000 Polys.

Stefan