ok... so I'm at a crowded bar taking pictures in low light of my band friends..... I'm too lazy to set up reflectors and its ok to annoy everyone with flash? interesting.
Key word in my previous comment:
Sometimes.
But as one who does a lot of band photos in low light bars, sometimes you have more control than you think. Asking whoever handles the lights for the bar to turn up the green LEDs (when they use those nasty magenta/green/blue LED spots on stage) if only the magenta and blue LEDs are on, for instance, can make a huge difference in your results.
It's the difference between this:
(5D Mark III + EF 50mm f/1.4. ISO 5000, f/2.2, 1/50)
(Which looked like this with auto WB before a lot of work with CT/WB adjustment as well as with the HSL tool)
And this (from the same stage):
(5D Mark III + EF 135mm f/2. ISO 3200, f/2.2, 1/100)
So can moving around a bit to use the light you do have to an advantage. Sometimes you do have to resort to post-processing wizardry. But even then, my (according to some) "pitiful" and "outdated" Canon 5D Mark II and 5D Mark III sensors with "horrible" low ISO DR do okay.
This place doesn't even have a real "stage", much less any stage lighting, unless you count those strip lights.
(5D Mark II + EF 50mm f/1.4. ISO 6400, f/2.2, 1/80. Lots of color correction.)
But there are some spots where you can get decent light angles from the TVs high on the wall above the mirrors behind the bar.
(5D Mark III + EF 135mm f/2. ISO 6400, f/2.2, 1/100. Pushed 1/3 stop in post.)
Another band in the same place after the strip lights had been removed:
(5D Mark II + EF 50mm f/1.4. ISO 5000, f/2.2, 1/125 and pushed 2/3 stop in post. Contrast and highlights reduced a bit and shadows pushed a bit more, and a lot of color correction.)
Sometimes instead of getting the shot you want (shadow on the face the entire night):
(5D Mark III + EF 135mm f/2. ISO 5000, f/2.2, 1/100. Contrast reduced, highlights pulled a bit and shadows pushed a bit more.)
You have to take the shots the light will give you:
(5D Mark III, EF 135mm f/2. ISO 5000, f/2.2, 1/100, Contrast reduced, highlights pulled a bit and shadows pushed a bit more.)
(5D Mark III, EF 135mm f/2. ISO 5000, f/2.2, 1/80. Pushed 1/2 stop and a green filter applied.)