 Traditional exposure metering and autofocus systems employ secondary sensors, whose readings are typically low-fidelity (e.g.a very small number of averaged readings from various image areas vs. fully resolved image information) and may not correspond to the actually recorded image, for example due to parallax issues, differing sensitivity towards polarization, differing spectral response, differing amplitude response, optical aberrations of optical elements in the sensing system, differing sensitivity towards stray light, or misalignment of the focal plane of the sensor.Most digital cameras allow users to capture and analyze image information from the same sensor as used for image recording in real-time.