Shaders Quality:
This setting has quite possibly the most major impact on both performance and image quality in Crysis, and the screenshot comparisons above demonstrate this quite clearly. It determines the overall quality of shaders used in the game, and Crysis is heavily dependent on shader effects for virtually every visual aspect. Note that this setting must be set to High or Very High for Anti-Aliasing or Edge AA to work in the game. The most significant impacts of this setting at each level below Very High are:
High: Detailed raised surfaces such as pebbles at the beach or those under trees in the forests are not as realistic due to removal of Parallax Mapping, and the number of lights affecting any object is reduced.
Medium: Disables HDR Lighting and removes ambient occlusion lighting; both changes significantly affect the general appearance of the game.
Low: Additionally, this level replaces the sky with a static background which is much less realistic, reduces texture filtering quality, changes the vegetation color so that it is doesn't blend as well, and even makes the HUD elements (e.g. your Health / Suit Energy indicators) more jagged.
