svl. yrs ago, katerina showed that poser IBL implementation very lo-res, with hole in polar area, such that even 400X400 map was overkill.  my advice: do not use IBL in poser 8 or later.  bill erred in saying IDL wasn't present in poser 7.  stefan added GIvariables to P7 for those courageous enuff to try them, but almost nobody did (unsupported).