A while ago I was playing Rise of the Tomb Raider and noticed a really nice effect when Lara is near a cave's exit: the environment outside lerp from very bright to the correct luminance when she is out. An example can be seen here: https://i.kinja-img.com/gawker-media/image/upload/peafu9itvcrf8iasfibd.gif
I'm especially interested in the 'inside the cave' part.
I'm really curious about how it can be implemented: is it a tone mapping or a bloom tweak? Or maybe neither of them?
Does someone know something about it or have worked on something similar?
Anything is well accepted! Thank you.