Logarithmic Depth Buffer for Orthographic Camera

So I had tried to implement the logarithmic depth buffer solution, but I realised that my camera is orthographic. So the math should be different as compared to the one used for perspective camera.

From Outerra’s article, The DirectX formula is z = log(C * w + 1) / log(C * Far + 1) * w

Does anyone know how to modify it for use with an orthographic camera?