https://www.moddb.com/games/heroes-of-might-and-magic-5/addons/fantasyfx-20#downloadsform

Reshade shaders for Heroes V.

Install:
1. Install Reshade, to the Heroes V/bin folder (you can delete the reshade-shaders for faster loading)
2. Copy the files from the zip, to the folder.
3. Ingame you can open the reshade menu with Shift+F2 and choose a preset, activate the Performance mode for more performance