[Matthew Burton mcfaul]

10 years later and I have the same issue – the DOF creates blurs that are clearly made up of a small number of feint copies. Even if this is mathematically accurate, it does not match the soft, continuous equivalent in real footage. An (untried) workaround, I realise, is to make a copy with and without blur, then comp these together with a difference blend mode. This will generate a map to apply a second blur only to the DOF-blurred areas to smooth them out a bit.