Gerald,
You get around the ‘lack of control’ by shooting as many dress rehearsals as you can. You also use dress rehearsals to get those close-ups your clients desire because camera set-ups are infinitely easier without the audience present. If you notice, in Ian’s piece there are slight variations in exposure between the main shot and the different cut shots. Since live performances aren’t exactly the same each time there will be differences in performance, where the light hits the talent and a host of other stuff. So it’ll never be perfect, but you can narrow down those variables considerably by shooting the dress rehearsals. It’s more work, but it justifies itself when it comes time to get busy in the editing bay.
