Equal redshift angular power spectrum for the fifth redshift bin of Euclid (DR1). We show the full calculation result from CLASS as a black solid line, and the Limber approximation result as a purple dashed line. The green dashed line corresponds to the recalibrated version of the flat-sky approximation. The various grey lines represent the contributions, from observational effects, to the exact solution (calculated using CLASS). The L-L contribution in this correlation is too insignificant to be visible on these axes.