Exposure when the lights are doing the work

Stage lighting is not normal light. Your camera's meter does not know that.

If you let the camera decide your exposure in a pit, you will get faces that look like they were lit by a torch in a tunnel. Sometimes blown out, sometimes underexposed, almost never what you saw with your own eyes.

Here is how to take that decision back.

Manual mode, not auto

Shoot manual. M on the dial. You decide what the camera does, not the meter. Three things to set, each with trade-offs:

Aperture

Wide open works most of the time great if you shoot in a dark room. f/1.4, f/1.8, or f/2.8 depending on your lens. A low aperture in a dark room pulls in light and isolates the face from the background.

The trade-off: very shallow depth of field. If you want the drummer behind the singer also in focus, or both members of a duo sharp, f/1.4 is too low. Stop down to f/2.8 or f/4. You give up some light. You get more of the frame in focus. Decide per scene.

Shutter speed

1/200s is the safe floor. 1/320s if the artist is moving fast.
But your own steadiness matters. When I shoot with the Sony bodies, which are light, I can hand-hold lower shutter speeds without losing sharpness. When I shoot with Colin's Leica, which is heavier, I am a little shakier and I bump the shutter up a notch to compensate.
If the artist is bouncing around the stage, push higher: I sometimes even shoot on 1/500s or more. Sometimes blur is what you want, it makes the photo dynamic. Dial down your shutter speed if you are after that.

ISO

This is the variable. The one you adjust most as the lighting shifts.
How high you can push depends entirely on your camera. With our Sony A7 III, I rarely go above 3200. The noise starts to look pixelated and ugly. With the Leica SL2-S, which has a cleaner native shadow response, you can easily go much higher.

Know your camera's ceiling. Test it at home on a dimly lit scene before you find out at a show. The number is different per body, and it is non-negotiable: above your ceiling, the files are not usable.

The rhythm during a show

Once aperture and shutter are set for the kind of frame you are after, leave them alone for a bit. ISO is what moves as the lighting shifts.

Most cameras let you map custom shortcuts to dials or buttons, so you can adjust ISO (or jump back to a saved preset) without taking your eye off the artist. Spend twenty minutes in the menu the first time you set up a body. Map ISO to a dial. Map a "reset" preset to a button. Once you have done it, you can move through changing light without ever looking down.

Reading the rig in 30 seconds

When you walk into the pit, the first 30 seconds of song one is for exposure, not for shots.

Take a frame, check the back of the camera, adjust. Take another frame, check, adjust. Get the artist's face properly exposed, then stop testing and start shooting.

Some photographers spray the first 30 seconds at full burst hoping one will land. Do not be that photographer. You waste card space and you miss the moment you should be watching for.

When the lights drop out

Sometimes during a song the rig will drop almost entirely. A ballad. A breakdown. A moment of stillness on stage.

You have two options. Either push ISO up a stop and a half, or accept that this shot is not for you and put the camera down for ten seconds.

Putting the camera down is allowed. Sometimes the best frame is the one where you watched the moment with your own eyes and remembered it.

Practice before you matter

Exposure is a muscle. It is built by reps.

Go to a small show with no pressure. Shoot it manual. Mess it up. Look at the frames the next day. Go again. After ten or fifteen shows, you stop thinking about exposure and start thinking about the image. That is the only goal.

If you want to learn this faster, the Collective shoots together on real shows with people who have done it for years. Apply if it sounds like you.