Co–Nd-liquid alloy ion sources (LAIS) were operated of a special specimen holder in situ in a 1 MeV transmission electron microscope. The dynamics of the tip shape in dependence of the ion emission current, spatial shifts of the liquid cone and the process of double cone formation have been observed. This results in a better understanding of the ion emission processes from Co–Nd LAISs in a large range of ion current. A linear dependence of the decrease of the cone half-angle α and of the increase of the jet length l and of the diameter d on the increased ion emission current was found. No emission of microdroplets at the shanks of the Taylor cone and behind the cone has been detected.