An imaging system (100, 200) for imaging electromagnetic energy, comprising: a detector for receiving the electromagnetic energy and generating sampled data in accordance with the electromagnetic energy so received, the detector being characterized by a threshold point such that the sampled data is in one of two states: i) below threshold, when the intensity of the electromagnetic energy so received is less than the threshold point; and ii) above threshold, when the intensity of the electromagnetic energy is greater than the threshold point; and saturation optics for providing a characteristic of the sampled data, wherein a characteristic of the sampled data when below threshold is different from the characteristic of the sampled data when above threshold, wherein the sampled data comprises a sampled point spread function ("PSF") wherein the saturation optics comprise a pupil function having an inner region and an outer region, wherein the characteristic of the sampled PSF when below threshold is associated with the inner region of the pupil function and the characteristic of the sampled PSF when above threshold is associated with the outer region of the pupil function; and wherein the outer region of the pupil function is tailored to affect the sampled PSF when above threshold, wherein the saturation optics comprise an arrangement of segments providing a multi-fold symmetry, wherein the sampled PSF when the data is above threshold exhibits a predetermined pattern, wherein the predetermined pattern comprises a digital watermark, wherein the digital watermark is viewable by illuminating the imaging system with off-axis and out-of-field illumination. a detector for receiving the electromagnetic energy and generating sampled data in accordance with the electromagnetic energy so received, the detector being characterized by a threshold point such that the sampled data is in one of two states: i) below threshold, when the intensity of the electromagnetic energy so received is less than the threshold point; and ii) above threshold, when the intensity of the electromagnetic energy is greater than the threshold point; and saturation optics for providing a characteristic of the sampled data, wherein a characteristic of the sampled data when below threshold is different from the characteristic of the sampled data when above threshold, wherein the sampled data comprises a sampled point spread function ("PSF") wherein the saturation optics comprise a pupil function having an inner region and an outer region, wherein the characteristic of the sampled PSF when below threshold is associated with the inner region of the pupil function and the characteristic of the sampled PSF when above threshold is associated with the outer region of the pupil function; and wherein the outer region of the pupil function is tailored to affect the sampled PSF when above threshold, wherein the saturation optics comprise an arrangement of segments providing a multi-fold symmetry, wherein the sampled PSF when the data is above threshold exhibits a predetermined pattern, wherein the predetermined pattern comprises a digital watermark, wherein the digital watermark is viewable by illuminating the imaging system with off-axis and out-of-field illumination.