Cut-off frequency (top), maximum amplitude (middle), and mean amplitude of the grass (bottom panel) versus duration of the studied light curve for CID 546 (blue squares), and CID 8669 (purple asterisks). The cut-off frequency of KIC 5892969’s power spectrum is not visible therefore only the maximum amplitude of the grass can be properly calculated (red triangles). Each line is the linear fit to the observed data points. The mean amplitude of the grass for CID 546 has been increased by 20 ppm to properly observe its behaviour.