[en] Differences of the deformation parameters for the 2⁺₁ states of even-even spherical nuclei extracted from electromagnetic excitation βsup(em)₂ and from proton scattering βsup(pp')₂ are discussed. It is found that the ratio βsup(pp')₂/βsup(em)₂ is equal to about unity and that there is a small isotope dependence for several incomplete shell nuclei. (orig.)