CTE correction (m_corrected−m_uncorrected) applied to objects detected in the F814W frame, shown as blue stars. The red circle indicates ULAS J1120+0641. Yellow crosses represent the median correction in the indicated bins of 0.5 mag (upper) or 200 pixels (lower). Upper: correction as a function of corrected F814W magnitude. Lower: correction as a function of Δy, the number of pixels from the readout register.