As others have pointed out Reality is the plug-in that connects your scenes with Lux. The plug-in provides a complete system that automatcially converts your Studio materials and then provides you with a material editor so that you can fine tune the materials to your own liking. 

Please be aware that you need to use the official release of Studio 4, 4.0, not the beta 4.5. When Studio 4.5 will be out of beta there will be a free update for Reality to support that version. 

Reality is available here: http://www.renderosity.com/mod/bcs/reality-2-for-daz-studio/92598

If you need any help don't hesitate contacting me. We also have a great thread here: 

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2849428

And there are the forums at my website: http://www.preta3d.com

Be sure also to check out our YouTube channel

All the best.

Paolo

https://www.preta3d.com
FB: https://www.facebook.com/RealityPlugIn
Tw: @preta3d
G+: https://plus.google.com/106625816153304163119
The Reality Gallery: https://reality-plug-in.deviantart.com