Well, GI is the way to go in Carrara. Not only are skylights (and indirect, i worked with that a little as well) great as GI, but they finally enabled me to get the hair fully resolved with reasonable rendertimes and beautiful illumination/reflection/shadows.

By searching the user manual pdf I found the control for turning off the defaulted 20% ambient. That made a difference right away. The manual tells you the same thing stated above....it's good to have it on for staging your scene, but turn it off for final render.

However, my searching in the PDF and in all the controls did not turn up anything on "interobject reflection." ren_mem, can you say what you meant by that? Also, I have not had time to follow your suggestions in post 41 above for anisotropic, but will pursue at another time. Thanks for you suggestions, they have been very accurate.

For all the results below, I employed only one light and did not move it for the entire run. It is positioned about 'four feet' above her head and about '8 feet' in front of her. While I tried once or twice switching, it is a raytrace distant light.

My research is divided into three after that.

Part A, I adjusted nothing in Poser, but made many small-move adjustments in Carrara, rendering each time. Increasing the power only sent the render time up, so I concentrated on how to keep every control on both the light and the render-features as low as possible, but still obtain excellent results. I found I could not turn Full Raytrace or Indirect on at all, nor did I need to. Just skylights. I finally came to the end of Part A with the render below: Render time, 10 minutes, 4 seconds

In Part B, I adjusted nothing in Carrara, but tweaked hair settings in Poser. This went on for a long time, but the upshot is, I DECREASED the strand count from 12,675 overall to 7,209 overall. Obviously, I did this to lower the burden on the render engine dealing with so many strands. To compensate for thinning out the strand count, I widened the rootwidth from .6 to 2.0 and the tipwidth from .1 to .3. Otherwise, I made no changes to Clumpiness, Kink, etc. Admittedly, I've now got 'spaghetti' instead of 'capelini', but at some point my madness must have a limit! I think it looks good. As a result, I was able to get render time down to 8 min, 13 seconds on the render below:

In Part C, I wanted to drive down the render time further. There was an unsuccessful foray into making the hair not receive shadows, and also changing the setting on backfaces from Smart to Hide to Show and back to Smart. I did have some success, however, with gradually turning down the shadow intensity and the photon count (down to 1000). Here is my stopping point, rendertime 6 minutes, 49 seconds.

[[[ just for kicks, before heading to bed I cranked up all the settings, turned on Full Raytrace and Indirect, and let her rip. The lovely render below greeted me this morning. Rendertime, 1 hour, 28 minutes and 41 seconds. Sigh. It is beautiful, even without any attempt to give her authentic skin. The lighting and perfectly resolved hair and shadows make it fine. ]]]

My hat is off to the Carrara GI render engine.

::::: Opera :::::