We report on experimental advances in scanning electron microscopy with polarization analysis that allow the observation of ferromagnetic domains in external magnetic fields of about 0.1 T. This is achieved by using a modified electron optics that produces a magnetic field at the sample surface that is spatially confined on the length scale of 0.1 mm. During imaging, primary and secondary electrons pass through the magnetic field without significant disturbance. We demonstrate that the primary electron beam may be used to keep track of the generated magnetic field. As an exemplary application, the switching processes of rectangular Permalloy elements are analyzed.