Since version 5.8.0 is an older release, you typically won't find the direct link on the main ReShade homepage. Instead, you can find it via: HOW TO FIX FIVEM RESHADE DOWNGRADE TO 5.8.0 ISSUE!
Introduced new add-on APIs and support for rendering effects with different dimensions than the back buffer. reshade 5.8 0 download
Adds realistic shadows to crevices and corners. Since version 5
Many GTA V roleplay communities specifically recommend version 5.8.0 as it bypasses the "black screen" or menu-opening bugs often found in later 5.9.x or 6.x builds. Key Features and Capabilities Adds realistic shadows to crevices and corners
ReShade 5.8.0 allows gamers to inject advanced visual effects into almost any Direct3D 9, 10, 11, 12, OpenGL, or Vulkan game. Popular effects available include:
Allows for real-time adjustment of saturation, levels, and "Technicolor" filters.
Simulates cinematic focus by blurring objects far from the camera.