the above render is excellent, but I can spot several errors in the render/lite settings,
including those mentioned by marcelo.  correcting said errors will increase render time by
1 or two orders of magnitude, hence one must ask if the extra render time is worth it.

p.s. after mark mentioned that C4D might be better for photorealistic renders, I checked
out their gallery here and was seriously underwhelmed.  maybe i just looked at a bad
page of renders done by beginners, but they didn't even look as good as carrara renders IMVHO.
however, I know they can get much better results, having seen some excellent porno stuff
done in c4d that makes poser stuff look laffable.