Systems, devices, and methods for detecting light obtain a first light-measurement objective, wherein a light-measurement objective defines one or more of an intensity of emitted light, a spectrum of emitted light, a spectrum of detected light, and a reflectance angle of detected light; obtain a second light-measurement objective; obtain an angular-dependence objective, wherein the angular-dependence objective defines a difference between a first light-reflection angle and a second light-reflection angle; select first settings values for one or more first illumination-emission devices and one or more first illumination-detection devices based on the first light-measurement objective; select second settings values for one or more second illumination-emission devices and one or more second illumination-detection devices based on the second light-measurement objective; and select a speed of an object conveyor based on the angular-dependence objective.