  Advances in upcoming weak lensing surveys pose new challenges for an accurate
modeling of the lensing observables. The wide sky coverage of Euclid makes
angular scales down to $l_\mathrm{min}=10$ accessible. At such large angular
scales, general relativistic effects manifest themselves, and the lensing
magnification cannot be correctly described by the standard lensing convergence
only. The impact of line-of-sight velocities on the magnification angular power
spectrum, referred to as the Doppler magnification, is already well recognized
in literature. In particular, it was suggested that the Doppler magnification
could be extracted by measurements of both cosmic shear and magnification. In
this work, we point out two previously neglected aspects with respect to this
method. Firstly, the impact of the Doppler magnification is reduced through
non-vanishing cross terms with the standard lensing convergence. This is
particularly relevant when the sources are averaged over a bin of width $\Delta
z\approx 0.1$, such as in Euclid's tomographic weak lensing survey. Secondly,
general relativistic potential terms slightly enhance the signal. We present
numerical calculations of all relativistic effects in the weak lensing angular
power spectra on large scales.
