Why is HDRI lighting so effective?
As a 3d artist without formal training, my approach to lighting has mostly been a process of trial and error. On the other hand, I suspect that 3d production houses have a much more constrained approach to lighting that involves some best practices for lighting certain types of scenes, e.g. interior vs. exterior, product vs. characters, etc.
Despite the fact that I will often experiment with different combinations of physical lights, bounce cards, sunlight, (etc.) during the initial lighting pass, there is some major proportion of scenes that I will ultimately light with only an HDRI, often because it simply looks better and renders faster. After reading dozens of blogs from Corona, Bertrand Benoit, and others, it seems that HDRI (only) lighting is fairly common, and if additional light sources are included, it is mostly to enhance a particular highlight, or fill a dark patch.
At the very least I would curious to know if HDRI renders faster in Corona than physical lights.