first range of optical paths 512 or second range of optical paths 522 first light ray 532 is incident on first extractor 510 and is extracted with a certain first extraction efficiency second light ray 534 is incident on second extractor 520 and is extracted with an extraction efficiency substantially less than the first extraction efficiency similarly second light source 540 at a second edge location generates both third light ray 542 and fourth light ray 544 third light ray propagates along one of second range of optical paths 522 while fourth light ray 544 is not propagating along either first range of optical paths 512 or second range of optical paths 522 third light ray 542 is incident on second light extractor 520 and is extracted with a certain second extraction efficiency fourth light ray 544 is incident on first extractor 510 and is extracted with an extraction efficiency substantially less than the second extraction efficiency the concept depicted in the configuration of fig5 may in some embodiments be utilized to selectively illuminate certain portions of lightguide 500 for example if light comes from first light source 530 but not second light source 540 e g first light source 530 is powered but second light source 540 is not then the comparatively higher extraction efficiency of first extractor 510 vis u00e0 vis first light source 530 results in that.