I couldn't see the dog on my monitor (1.8 gamma), hence I took the liberty of using the APS "exposure" filter (incl. exposure, offset and gamma sliders). on left is img adjusted with 2.2 gamma, middle is unaltered, on right is img adjusted with 5.0 exposure. so I'm thinking the poser tone-mapping/gain is more like the "exposure" slider in APS and unlike the "gamma" slider in APS.  there are some errors in description of  poser tone-mapping func. in manual, but it implies it's an exposure tool and cannot simulate gamma corr.