With new tools, we must use new techniques. It isn't fair to just flip on GI, and ignore how that changes things.

Looking over my scene, I found that the ground was white. Now without GI, that really doesn't matter, but with GI on, this was producing an excessive amount of ambient light. I changed the ground to a dark gray.

Further, my scene is a studio with walls. IBL was there to simulate the reflection of light off the floor and walls. But with GI, I have the real thing, and the IBL is just pilling on, making altogether too much light. So I simply turned off the IBL, and let the GI take care of the ambient light bouncing off the walls and floor. So now I just have a single spotlight in the scene.

Finally, the GC was producing sRGB values for all the surfaces, which compensate for how luminance works on a screen. We want the output of each shader to be a linear luminance, not an sRGB luminance. So I turned off the output GC stage of my shaders. This was just a few clicks using VSS. I left the input stage anti-GC on the shaders. This lets the shaders anti-correct the incoming textures so that they are linear color space values.

Then I enabled Exponential Tone Mapping. Not HSV Exponential, but Exponential. As far as I can tell, the math here is identical to the final GC stage of Poser Pro. So my linear values coming from the shaders are finally converted to sRGB color space by Poser 8's tone mapping feature.

The resulting render is more realistic than what I started with. The work required was modest, but necessary. It was wrong to combine IBL (fake ambient light) with GI (real ambient light).

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)