Upper panel: contour plot of the 2D histogram of the number of pixels at original resolution, binned and smoothed (black lines). The contours and labels for the original distribution are the same as in Fig. 2. Overlaid are the contours for the case after convolution and rebinning, corresponding to 0.5 m aperture, also binned and smoothed (blue contours). Lower panel: contour plot of the 2D histogram of the number of pixels at original resolution, with pixels divided into two groups (red & black contours): pixels with B_vert > 1500 G after convolution to 0.5 m telescope aperture are shown with red contours. These correspond to the pixels outlined in red in the middle panel of Fig. 5. The remaining pixels correspond to the black contours. The vertical dash-dotted line indicates the field strength of 1500 G chosen for the separation.