Luminosity function of all reliably measured stellar sources in the survey images. Brighter than F606W ≈ 18, stellar sources have an increasing number of saturated pixels, leading to less accuracy at increasingly brighter magnitudes. Fainter than F606W ≈ 26, the luminosity function begins to roll over, indicating increasing incompleteness for dimmer stars. This incompleteness level changes with the local density of stars, leading to deeper photometry in less crowded regions. However, the exposure time limits photometry to brighter than F606W ≈ 27.