Exporting Displacement map in 16 bit Tiff with Alpha Displacement Exporter plugin :

Configure the map to export (Zplug/ MULTI DISPLACEMENT 2/Map Size (Max Map Size slider), Overpaint border thickness (Border slider) and Map quality (DpSubPix slider)).

(For more about installing and using the Displacement Exporter plugin go to ZbrushCentral: http://206.145.80.239/zbc/showthread.php?t=029789.)

Right, configure the Displacement Exporter plugin on the ADE panel (Alpha/DE Option button): PN16 (this is predefinied configuration). Configure this as follows: set the Configuration Status to ON (this way the Red channel will contain the positive, and the Green channel will contain the negative displacement map) and set options: Smooth, Seemless and Vertical Flip to Yes. Export (Export Active Set button or Export Current button).