While our method has been exemplified through the widely used ferrioxalate actinometer in intensified reactors, its applicability spans other chemical actinometers across varied configurations. Essential prerequisites include knowledge of the actinometer's absorption data and its products, as well as the light source's spectral distribution. Moreover, meticulous detailing of the geometries of the light source, light sensor, and photoreactor facilitates a representative portrayal within streamlined ray-tracing simulations.