A free mod for Witcher 3, by ZephyrTX.

Zephyr Utimate Realism 1.32 is a game preset created by Zephyr, a well-known developer. It contains all the necessary tools to make the game run smoothly on any hardware. The main focus of the developer is to give the users a high-quality gaming experience.  The developers have made sure that all the necessary tools are included in this app, from lighting and shading to fog effects and motion blur.

The developers have focused on realism, so you can expect a slight loss of 5 to 10 fps. This app is lightweight, focused on realism, and includes different effects that make your experience quite comfortable for your eyes.