All flickering problems is caused most by AA methods for example TSR.It add frequency filter which change lighthing to strobe. It is visible when Mixing everything when trying to achieve more dark scenery. Adding more effects that make disproportions between light and shadows add noise to the scene - VSM and raytracing(distancefield) Illumination,shadow methods also add that type of filter - which also apply similiar effects. The question is how to fix that pulsar.
Flicker