Abstract: An infrared imaging system is provided. The system includes a sensor configured to receive light emitted by a scene and at least a portion of scenic flux to generate image data, a light source configured to provide calibrating light to offset at least a portion of the scene flux, the light source positioned such that an output of the light source is at a pupil of the infrared imaging system, and at least one image processing device. The image processing device is configured to receive the image data generated by the infrared sensor, determine at least one change in the scenic flux as received by the infrared sensor, determine if the at least one change in the scenic flux results in a change in pixel response of the infrared sensor that exceeds a response threshold, and if the change in pixel response exceeds a threshold, generate an updated calibration table.