Comparisons of the Gaia DR2 median G magnitudes and the flux-calibrated Kp magnitudes from the K2 mission, with the inset showing the distribution of the absolute differences. Colour-coding marks the absolute differences between the flux-calibrated Kp values and those found in EPIC: there is a clear systematic difference between the two Kp values towards, the faint end. Red outliers indicate agreement between the Kp values, but difference from the Gaia brightnesses. Crosses mark the Sgr stream stars in Field 7. The black line marks equality.