When running native D3D9, deband.fx smooths out fog and shadow gradients perfectly. But when using DXVK (hooked via global Vulkan), the debanding effect becomes incredibly weak, as if the thresholds are failing to detect the banding.
D3D9 •
i.imgur.com/YIdTuJY.gif
DXVK •
i.imgur.com/XvQIjxl.gif