  We systematically compare filtering methods used to extract topological
excitations from lattice gauge configurations. We show that there is a strong
correlation of the topological charge densities obtained by APE and Stout
smearing. Furthermore, a first quantitative analysis of quenched and dynamical
configurations reveals a crucial difference of their topological structure: the
topological charge density is more fragmented, when dynamical quarks are
present. This fact also implies that smearing has to be handled with great
care, not to destroy these characteristic structures.
