Top: quiet Sun limb darkening measured in PK-027 (green, solid line), PK-010 (violet, dotted line), and PKR-011 (red, dashed line) good images. Intensity values are normalized to the median of values measured at the disk center (μ ≥ 0.95). The error bars show the dispersion of measured values. Bottom: ratio of the median of quiet Sun limb darkening measured in PK-010 to PK-027 (diamond) images, and in PKR-011 to PK-027 images (asterisk). The error bars show the dispersion of values from error propagation. The dashed line would represent perfect agreement between the two compared sets.