Trench Lighting Help

Hi guys, I’m working on a trench for a movie and I need a lot of help with the lighting. I need the lighting of this

to look more like this

(movie is Passchendaele, I claim no ownership of this movie)
So I need the lighting to be brighter at the top of the trench. Any suggestions/ideas?

I would use the compositor, here is a result I got from the render you posted:

compositingexample.blend (475 KB)

Feel free to check out the nodes I used, mainly the colour balance and colour correction nodes helped alot.

That works, thanks! So now that its accurate, does it look like a trench in your opinion?