Traditionally, photosynthesis has been characterized using gas exchange measurements, but this procedure is slow and laborious and impractical for mapping photosynthetic parameters at the canopy or whole plant level. In this study, photosynthesis is characterised in relation to plant architecture and heterogeneity of dynamic canopy light environment. Investigation of evolving canopy irradiance, and the photosynthetic and architectural response is examined. First, using single genotype (Nipponbare) with leaves at different canopy levels, through vegetative and reproductive growth, and repeated using 4 genotypes with contrasting morphology with similar Harvest Index. Weekly 3D imaging with a novel digitization platform is used to characterize key plant architectural traits and phenology. Gas exchange was measured with LiCor 6400, and diurnal measurements of leaf chlorophyll fluorescence were made with a multi-head pulse modulated chlorophyll fluorometer by applying saturating flashes every 30 minutes in a glasshouse environment. Irradiance at varying canopy levels was tracked throughout growth. Dynamically, as intercepted irradiance reduces per leaf over time due to self shading, photosynthesis and leaf chlorophyll consequently reduces. However, the diurnal relaxation kinetics of the photoinhibition response to variation in intercepted irradiance at varying canopy level show clear variation across genotypes, and at different canopy levels in a single genotype. We are presenting results from the 3D imaging platform, characterization of photosynthesis from fluorescence using curve fitting techniques to model ETR as a function of Irradiance, and incorporation of these aspects into a functional dynamic model of photosynthesis.