Absolute (bottom row) and relative (middle row) rms variation in the intensity as a function of wavelength for Ca ii IR at 854 nm (left) and Ca ii H (right). The solid black lines denote the full FOV, and the red dashed and blue dash-dotted lines the field-free and magnetic locations, respectively. Top row: relative fluctuations versus (vs.) geometrical height. Black crosses: full FOV. Blue squares: magnetic locations. Red triangles: field-free locations. The ratio of maximum to average intensity is overplotted in the upper two rows with a black dashed triple-dotted line and black diamonds, respectively. The short bars in the lower right corners in panels e and f indicate the average range of scatter in the plotted data points.