I played around with it a little this morning, and since you mentioned text, I figured I would try that. It's a volumetric spotlight in a volumetric atmosphere. The settings for this, in the volumetric settings box, Intesnsity .5 Quality boost 6.0 I had the "show smoke and dust" option turned off. The shadow value was set to 500%. which definitely does make a digfference, and the Power of the spot itself was 200. I had to add some non shadow-casting lights around it so you could see the text, because all that light behind it would wash it out, but the lights in front don't seem to have afffected the volumetric shadowing at all. Rendered on final in about 5 minutes. I'm surprised really, because it looks more like an Ultra render. The "quality" setting in the volumetric options box does make a huge difference.