I have a video of a stage production that in hindsight I shot a little too dark. I was too concerned about not having ghost faces.

What would be the recommended way to brighten up the shot a little bit. I have played a bit with the brightness/contrast HSL filters. I seem to get better results with the HSL filter. When I play with the filters graininess seems to be the tradeoff.

Speaking in audio terms I almost want to decrease the dynamic range of the video. I want to boost the low light areas while reuicing the high exposure areas.

Are there any best practices ?