Eye Adaptation post process volumes make the viewport extremely bright

In 4.14 when entering the volume the screen brightens which is expected.

The problem is that in 4.15 it brightens more. So much so that some static meshes are rendered almost completely white.

I tested this on an R9 380, and was also able to reproduce on a Quadro M6000, and a GTX 980.

1. Open QA-Game
2. Open QA-PostProcessing
3. In the viewport, navigate to 1.2 - Auto Exposue Eye Adaptation
4. Move into the left side of 1.2
5. Observe the lighting changes

Expected Result: The viewport brightens
Actual Result: The viewport brightens too much