You could try the Soft Contrast plugin - turn off everything in the "effects" tab and use the vignette settings to equalize the light, but you would probably need to then raise the brightness of the entire scene.
You'll probably get the best results by copying the clip to a track above the original, correcting the low lit side to the brighter one, then use a mask with feathered edge to combine the two.
Or as you hinted at, create a black to white gradient in either Vegas or Photoshop that can be used on a higher level track - then play with track levels and compositing modes to see which give the best results.
That's a situation we face all the time, in shooting productions at schools.
Usually for us, the center of the stage is hot-lit, and the edges dark. Then they put girls with white dresses under the hot lights, and kids with black outfits in the unlit areas.
We always shoot with two cameras -- one with wide shot, which does show/suffer from the very uneven lighting, and the other for closeups and small-group framed shots, so we can tweak the iris as necessary for the tight shot.
(There are other reasons why we use two cameras as well, but this lighting conundrum is a good reason all by itself!)
I've done some amazing repairs with NewBlue Colorfast. Based on their integrated and adjustable Highlights, Midtones and Shadows MASKS, I can get busy with adjusting the levels, saturation and tint independent of each other. Do check out their tutorials.
I recently did a play with three cameras. Camera one is set with a limited amount of AGC and fixed iris for close-ups and variable zoom on certain shots, camera three is set for the bright scenes/parts only and camera two is setup for all the dark to medium light scenes. Cameras two and three are set for the width of the stage but zoomed slightly in.
The fixed iris on camera one allows for zooming without messing with the exposure. I also used an extreme exposure offset which gives great face exposure in bright lights including spot lights. AGC limit = on (24db) to prevent too much gain.
Camera One = Sony CX-900 - Closeup to medium wide shots. Also helps with the extreme dark scenes that the PJ-710 cannot handle. Also has the max exposure -offset.
Camera Two = Sony PJ-710 - Dark scenes with limited AGC to prevent over gain and too much noise. Also has exposure offset.
Camera Three = Sony PJ-650 - Bright scenes only. AGC set at zero with iris set to 4 to control the exposure.
Focus and white balance is locked on all three cameras. White balance is set for indoor light.
Stage is always hottest at the 'stage right' 2 thirds and darkest at the edges. Combined cameras gives me most of what I want.
Bottom line is, you really got to know your camera limits for this type of video. You can explain, beg or whatever to the person in charge of the lighting and then just do the best you can with it.
Theater lighting is set-up for theater not video! I told them, they know it, they do it their way anyway, they get the best I can give them, and we move on...
I set up a stage that would have the President of the Royal Society speaking to an audience I was to captue using 3 cameras. I had had the front of house position Lectern, diaz and the suspended 30' high ceiling floods/spots nicely positioned by a great lighting designer (nice one Brian!) who needed a tower and maybe 3 hours of adjustment to ensure I was getting a nice illumination in a pool around the lecture. This was setup and the hall locked . . yeah, right. . . . my team and I return to find that the diaz and lectern had been moved back several feet and well out of the illumination pool, to accommodate for 3 extra rows of a now well sold-out event.
I was into major ZEN mode.
OK, I say, but there was enough room to MOVE or add the 3 rows to the rear of the 300 seat "pack" back within the hall. After much persuasion and a short, pithy introduction 101 on lighting, from myself, the front of house team obliged and made adjustments to the seats; my team and I schlepped the diaz, lectern, set dressing and steps back into an agreeable position.
It looks over exposed to me, always avoid over exposure.
As a guide the back rows are correctly exposed, that's how the brightest part of the stage (front mid right) should have been exposed. Let the shadows fall where they may. There's always some opportunity to bring the shadows up, how much depends pretty much on how much the camera cost. Regardless of how much you've spent on the camera clipped highlights are never recoverable.
Having just completed my latest Nutcracker, the key thing about videotaping live events, when you have no control over lighting, is fresh in my mind. It all comes down to one word:
If you are shooting with a camera that doesn't offer this functionality, then ditch it and get one that does. If your camera does have this feature, use it.
I have a three-ring circus going, with two cameras, and a manual audio feed. As a result, I need to partially automate some functions. I fix the focus, set color balance to the indoor preset, and then set exposure to auto. However, to avoid the problem demonstrated in your snapshot, I use the "spotlight" function combined with a series of negative EV presets. The spotlight function is designed to avoid burnout, like you have in your video, when portions of the scene are lit with really strong light. You use the zebra patterns on the screen to alert you when this function fails. You then dial in negative EV settings until the zebras disappear. If the lighting changes, you have to be aware enough to set the EV compensation back to zero.
For static performances, like you were filming, there probably aren't too many lighting changes. However, for plays and ballet, the lighting changes all the time, and lighting often includes follow spots, etc. So, you have to be on your toes.
However, no matter how alert you are, unless you use the zebra function, you will be shooting in the dark, so to speak, without any clue as to whether you are over-exposing.
You can fix any slight under-exposure by using Vegas Color Curves in post. Remember, you can fix, to a degree, under-exposure, but you can never fix over-exposure. So, while correct exposure is what you want, if you have to make an error, make the scene too dim.
It's a poster child for bad lighting and exposure. Nothing can be done for the highlights. Dropping the shadow levels and gamma a bit can help the rest of the cast. Looks like a throwaway project to me, if you'll excuse the bluntness. Done a few of those myself . . .
Front right is a tad over exposed, but not throw away either. The grain is more of an issue I would think.
I do a fair few concerts and it is a very rare day when everything is ideal. I only get to lug in an average of 90min before show time in most theatres. Run around and set up 5 cams and only man one of them.
Lucky if you get some lights on to even white balance, and then most things are out of your control during the show.
Lighting guys who dont like to see the talent, just ghosts moving around in the murky shadows, or even worse, ones who think back lighting is the only way to go. Silhouettes are very cool....
FWIW. Thursday I had a rude obnoxious lighting guy. Dark as night, didnt care about anyone else, even laughing at the kids which I was hearing in my room sound mic. Rolled his eyes when I asked him to quieten down a bit.
Saturday night in same theatre I get another guy who is even looking at my monitors to see if the lightings ok and tweaking it if it was too dark.
What a difference it makes.
Even cheap cameras can be made to work OK.
Even the cheapest cameras do have "Ev Offset", dialling that down to around -1 (minus 1) will help with wide shots with hot spots. You could probably go a bit further but then tight shots could get pretty dark. On some of the not super cheap cameras you can assign Ev Offset to a knob which I've used to some effect.
Of course if your cameras has got zebras use them but for the love of all that you hold dear know what they're telling you. Some cameras have fixed zebras at 100 and others it's at 70, get that mixed up in your head and you can be making very bad decisions.
Jedman, you've missed the point completely. Schools don't have "lighting guys" who laugh at the kids. They have a scared-to-death 15 y/o at the board who has a lot of heart, no experience, no training, and their own fam damily in the audience; they fake it until they make it. I have turned a few of those kiddos into world-class TDs who went on to Webster U and eventually Broadway, using patience and persistence.
If I saw that kind of crap in regional theatre, I would throw a fit. But we all started in the same place, do you even remember??
Agree if it was a kid doing that, yes they need to grow up and may get better.
This guy was going on 30 and one of the "professional contractors" the theatre uses on a regular basis.
There are about 6-10 freelance lighting techs they use to spread the work out.
Its a lucky dip which guy you get when you hire the theatre, unless you (not me, the dance school) chooses to pay even more and hire their own guy.
I will have to learn better ways to deal with them though.