You can mix the passes.
However, you’d get better results using a film grain instead of the cycles noise. Either a filter in Photoshop or Gimp (g’mic), or blend an actual image of film grain in the Blender compositor.
However, you’d get better results using a film grain instead of the cycles noise. Either a filter in Photoshop or Gimp (g’mic), or blend an actual image of film grain in the Blender compositor.