  Angle-resolved photoelectron spectroscopy of aerosol droplets is a promising
method for the determination of electron mean free paths in liquids. It is
particularly attractive for volatile liquids, such as water. Here we report the
first angle-resolved photoelectron images of droplets with defined sizes, viz.
of water, glycerol, and dioctyl phthalate droplets. Example simulations of
water droplet photoelectron images and data for electron mean free paths for
liquid water at low kinetic energy (< 3eV) are provided. We present an approach
that allows one to gradually vary the conditions from shadowing to nanofocusing
to optimize the information content contained in the photoelectron images.
