The Julia Morgan Ballroom 465 California Street, San Francisco
Light has been a fascinating topic ever since I took Dick Peters architecture class at UC Berkeley -- we built light boxes with moveable openings and shifted the "sun" around the "building" to study the different effects of light. No computer simulation then!
Balancing the light is almost always a good idea, particularly when visual clarity is important. I've been in the Julia Morgan Ballroom at least two times before. As I entered for the third time, I immediately remembered the problem of lighting a space like this. It's large and ornately detailed with dark paneling - heavily draped windows on the south and west. In the top photo, notice the very strong natural light from the south facing windows producing blinding spots of light.
In the ballroom above, there is no balancing natural light from the north side and an insignificant amount on the west side. The artificial lighting is too meager to compensate for the cavernous dark interiors. See how the speaker is backlit and it's almost impossible to see his face. I wonder if this is how Ms. Julia Morgan originally designed the space? It's nice to think that perhaps the arches on the north side of the space were once windows.
Hall of Mirrors - Palace of Versailles
This problem was luxuriously solved over 300 years ago in the Hall of Mirrors at Versailles. Large arched mirrors were installed equal and opposite to the wall of windows. I guess Louis XIV had a good architect (Jules Hardouin-Mansart).