In nature, this issue does not happen because real IDL is not only caused by re-emission from objects but by scattering in the atmosphere itself too. And because bounces are infinite, and quality is 100%. So, in Poser you can

 - soften the direct shadows, set shadow intensity somewhat below 100%. This will not only reduce the shadow on the couch but will also reduces the darkness withng the porch.

 - increase shadow softness by increasing blur radius (you might have to go as high as 50) and shadow samples (take 10x blur radius), for the infinite sun light

 - increase bounces (render settings), which will increase the IDL level within the porch. Then the iDL will just overwhelm the shadows, makes the artefact less visible.

 - reduce IDL intensity (script > d3d > render firefly) to say 0.65. This will reduce IDL level within the porch.

The splotches as pointed out by BB are especially appearant in test scenes with strong color contrasts, and at low render settings. In rich textured scenes with high render settings, and some direct lights added in as well, Poser can do a nice job, and the rest can be fixed in post. Poser is nice for it's price, but not perfect for cheap.

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Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though