Accretion column geometries used in earlier cyclotron calculations. The slab 1-0 geometry is a bottom-illuminated slab. The slab 1-1 geometry corresponds to a slab illuminated by a seed photon plane in the middle of the slab. In cylinder geometry, the seed photons are injected isotropically from a line in the center of the cylinder. Spectra emerging from the cylinder geometry are characterized by the optical depth in the radial direction, while the total optical depth along the vertical axis is used to define the scale of slab geometries.