IDL is basically real global illumination, something users used to hack in Poser by using 50,000 lights all set to very low values. IDL is really only effective when used in conjunction with some kind of enclosing environment that bounces the light around the scene. I'm not going to get any more technical in my description as that'll just cause someone to tear me a new one.

You should definitely give IDL a shot, I think it's the most significant advance that's happened within Poser and is useful for any style of render... But in particular for what your trying to achieve. Download Bagginsbill's environment sphere, read the accompanying documentation on the site, dump ambient occlusion (IDL is superior), and read up on IDL...

https://sites.google.com/site/bagginsbill/free-stuff/environment-sphere