I made the map by dropping the major8 displacement map into the green channel of an empty Photoshop file and copying the minor8 displacement map into the red channel. 
Saved as TIFF, with only red and green channel enabled.

I stripped out everything except the displacement entry. Rendered in Front view.

I don't see a difference.

http://home.xtra.co.nz/hosts/polycount3d/HellColumn03_B_P6.ZIP

this one only uses one image
attached image shows the old one on the left 
I'll attach the node setup in the next post

the sphere in the middle is from this thread where we figured out how to get the maps from zbrush to poser,that renders even smoother than the column
http://forum.daz3d.com/viewtopic.php?t=25013&postdays=0&postorder=asc&start=0

& here's the zbrush displacement exporter code I'm using:
DE-HDDK-EBECAA-D88

I understand whats going on with %50 Grey, but do'nt have time to illustrate.  I'm hoping we get this;  but I may get a chance to do a couple scrnshts, on request, tomorrow or Monday.

At first I did'nt have much problem with Displacement, but then I noticed weird cracks on V3's face.  Today I happened to be poking at my P7 manual, and read the cracks were from too small a DIsplacement Value...more on that later.

The amount of Displacement is a product of the Displacement Value, multiplied by the shade of the Displacement map.  Theoretically, when using %50 Grey, you would also always use a Displacement Value of 0.  By changing that value, and then using %50 grey, you're still driving the node.

So, how do we avoid using the Grey part, of the image I posted, in my Material Room screenshot?  The answer is with the Blending Value of the Blender node, and a Transparency Map(To block the %50 Grey part,) as illustrated in the first srcreenshot of that link I'd mentioned.

Whistles!

I am soooo bookmarking this thread...good info here! :thumbupboth: