Eye Adaptation Fix for SE and VR

What is eye adaptation?

Eye adaptation is a postprocessing effect in Skyrim that adjusts how bright the scene appears based on where the player is looking. This is what causes objects or landscapes to appear darker when you look up at the sky or directly at a bright light source.

Why is eye adaptation a problem?

In regular flatscreen Skyrim, some imagespaces have a slow adaptation speed that causes the darkening effect to linger momentarily after looking at bright light sources. Some people may find this unpleasant.

In Skyrim VR, eye adaptation completely breaks the visuals because eye adaptation is applied to each eye separately. Thus, if one eye is looking at an area of the scene that is relatively bright while the other is looking at a darker area, both eyes will have a different level of eye adaptation applied. This has the unwanted effect of breaking shadows and lighting entirely in some scenarios. Even in cases where the level of eye adaptation is synchronized between both eyes, the effect is still unwanted because it effectively tries to simulate what your eyes do naturally by dilating or constricting your pupils in response to light. The end result of all this is that your eyes can really begin to hurt with areas in Skyrim that rely on eye adaptation quite heavily.

How does the fix work?

After a lot of testing with Skyrim's postprocessing and imagespace parameters, I've learned that eye adaptation relies on the contrast parameter of a scene to function. In particular, eye adaptation requires a contrast value of greater than or less than 1. 0 to apply any sort of eye adaptation to a scene. While I don't know exactly how it's used to calculate the final image, areas with particularly high contrast values will cause eye adaptation to engage quite strongly. Interestingly, areas with contrast values below 1 will cause eye adaptation to work in the reverse direction so that looking at bright lights causes the scene to become brighter. When setting contrast to 1. 0 exactly, however, eye adaptation no longer works at all.

This mod simply takes advantage of this strange quirk of Skyrim's postprocessing calculations and adds an MCM toggle for an imagespace modifier that locks the contrast parameter for the scene to 1. 0. When enabled, the imagespace modifier will always be active and eye adaptation will no longer engage. It can be disabled at any time.

How is this different from other "Remove HDR/Eye Adaptation" mods?

As far as I can tell, this is the first mod which can eliminate eye adaptation entirely from the game because it specifically works through the contrast parameter. Also, as far as I am aware and based on extensive testing, this is the only method to truly remove eye adaptation from the game forever.

Other mods typica