Radiatively heated ovens have been used as vapor sources for vacuum deposition of superconductive films, primarily tin and lead. They delivered uniform deposition rates in the entire range tested from tenths of angstroms per second to ∼100 Å/sec. For the experimental arrangement employed, a deposition rate of 1 Å/sec is found by calculation to correspond to an effusion rate from the oven of 2×10−5moles/cm2/sec. By effectively reducing the length of the oven opening to zero and increasing the ratio of oven diameter to opening diameter to about four, emission characteristic of a surface source was obtained for the same range of deposition rates. For one such oven of typical dimensions, a chart is included by use of which compromise may be made between effective source enlargement, due to self‐scattering effects at the source, and deposition rate.