I completely mess up with the white balance during an underwater trip.
I end up with the below video
I tried to play with the color correction tool (curves actually) and finally arrived at this result
It's still not correct but I can't find a way to make it better.
Does the gurus of this forum have any idea?
In my opinion you've done about a good as job as is possible with that footage. I spend half my life correcting underwater footage with Vegas color curves and my result was very similar to yours. Here's what my curves look like. My V12/V13 veg project is here. The horizontal sections of the curves are at 16 and 235. You can move the anchor points 1 unit at a time with the arrow keys.
Your blue water is still a bit too saturated. It goes past the green Cy box on the Vectorscope but it shouldn't really.
Perhaps a grading program such as Resolve could do better.
Maybe you try
http://www.semw-software.com/en/autolevels/
Gives shadows that are too red (as opposed to black) and highlights that are too cyan (as opposed to blue) in my opinion.
Like Nick, I too spent years correcting underwater stills, and i agree with him completely; and he has taught me a few things through his bubblevision channel. Look their for best practices in both pre- and post- white balance.
Thanks Nick for your wonderful curve presets and advices regarding the vectorscope that I always forget to check.
I also tried with Resolve but my limited knowledge of this software doesn't give me a better result than Vegas.
Next time I'll make sure to use the raw WB setting on my Gopro; lesson learn.
If you have a lot of footage that is in the same ballpark as the still you posted, you could apply that curve I made to them as a starting point. Then start by moving the "elbow" points of each curve (where it changes from curve to horizontal) left or right with the arrow keys on your keyboard while watching the histogram. In general (i.e. not always) you'll want to fill up the 16-235 section of the histogram with each primary (red, green, blue) without crushing at the ends. Then adjust the tangency on each end of the curvy bit. Hope that makes some sort of sense. I work with "All" scopes on display as each plays its part.
By the way, that's probably the most extreme curves I've ever applied. A good colour correction filter such as Backscatter's Flip4 system would help. Or as a cheap option if you don't need to remove the filter you could get hold of a piece of 008 Dark Salmon Lighting Gel Sheet by Rosco (or even butcher one of their free swatch books) and fit it over your lens inside the housing.
How is that?
I am no expert but this is all done in Vegas, no 3rd party plug in. I used 3x Color Balance (Shadows, Mid & High), Color Corector and Brightness & Contrast plugins.
I actually quickly did it on my Surface Pro 3 but it only has MovieStudio on it, no scopes to check my work. The color of the water can now be easily adjusted with the Color Corrector, Highlight wheel.
Edit: Did a redo on my NLE workstation with VP13.