A small probe centered on an atomic column excites the bound and
unbound states of the two-dimensional projected potential of the
column. It has been argued that, even when several states are excited,
only the 1s state is sufficiently localized to contribute a
signal to the high-angle detector. This article shows that
non-1s states do make a significant contribution for certain
incident probe profiles. The contribution of the 1s state to
the thermal diffuse scattering is calculated directly.
Sub-Ångstrom probes formed by Cs-corrected lenses
excite predominantly the 1s state and contributions from other
states are not very large. For probes of lower resolution when
non-1s states are important, the integrated electron intensity
at the column provides a better estimate of image intensity.