In embodiments of imaging structure emitter calibration, an imaging unit includes an emitter structure that direct emits light, and optics direct the light along a light path in the imaging unit to illuminate a projection surface. A reflective panel reflects a portion of the light to illuminate a light sensor. An imaging application receives the sensor data from the light sensor, where the sensor data corresponds to emitted light output from the emitter structure. The imaging application can then initiate a calibration input to the emitter structure to adjust the emitted light output from the emitter structure.