Illustration of the vertical trace flexure procedure; here a science observation of ZTF18abqlpgq. Blue markers show the pseudo-magnitude computed inside the spaxel traces, the lower the brighter. The orange curve is a cubic spline interpolator. The gray vertical bar shows the minimum of the cubic interpolation. In this illustrative case, the dome-based trace mask must be shifted by −0.3 pixels to account for vertical flexure.