  The gamma p ---> pi+ pi- p reaction, in combination with data from the pi N
---> pi pi N reaction, allows one to obtain the s- and d-wave amplitudes for
the N*(1520) decay into Delta pi with absolute sign with respect to the
N*(1520) ---> N gamma helicity amplitudes. In addition one obtains the novel
information on the q dependence of the amplitudes. This dependence fits exactly
with the predictions of the non-relativistic constituent quark models. The
absolute values provided by these models agree only qualitatively, and a
discussion is done on the reasons for it and possible ways to improve.
