Spectra (upper panel) from grmonty (points) and sphere (solid line) produced by Comptonization of soft photons in a homogeneous, spherical cloud of hot plasma. Computations are done for: plasma optical thickness τ = 10 ⁻⁴, plasma temperature Θ _e = 4, and the central source radiative temperature kT _r / m _ec = 10 ⁻⁸. Lower panel shows the fractional difference between the two spectra.