I have not bought a Nikon D600, despite the temptation, but according to the website Digital Focus Nikon has finally identified the real source of the dust. "This is the room of the surface treatment," says Delphine Bordes Nikon France. "That's rough coating which in rare cases has flaked and produced many dust. "Blame the interior paint in short. And not in the mirror damping system or a possible surplus of grease in the mechanical shutter or to mysterious silicone tasks, etc.