Plants use diffuse light more efficiently than direct light, but it is often difficult to quantify this experimentally because of confounding effects such as differences in light intensity. Li et al. combine greenhouse studies with model simulations to examine photosynthesis in tomato (Solanum lycopersicum) crops, and conclude that higher production in diffuse light results primarily from a more homogeneous horizontal and vertical light distribution. In addition, plants acclimate to a high level of diffuseness by gaining a higher photosynthetic capacity of leaves in the middle of the crop and a higher leaf area index. Diffuse light also results in lower leaf temperatures and less photoinhibition at the top of the canopy when global irradiance is high.