EACF level for Kepler data, homogenized to a uniform observation duration of 48 months, expressed as a function of ν_max. The x-axis also shows the corresponding log g. The color designates the stellar magnitude, as indicated by the theoretical level overplotted on the diagram. The three vertical dotted lines indicate, from low to high frequency, the mean location of the red clump, the transition between subgiants and red giants, and the Sun. The vertical solid line indicates the Nyquist frequency of the long-cadence mode of Kepler. Different stellar types and classes are shown parallel to the x-axis, with an independent color code.