1. A common path, interferometric imaging system for imaging a sample, comprising: an illumination source that generates light and directs it to the sample, which splits the light to form a substantially unscattered light component and a substantially scattered light component; an optical imaging system having an object plane, an image plane and a pupil, wherein the sample is substantially located in the object plane, with the optical imaging system being configured to collect and image the substantially scattered light component and the substantially unscattered light component, wherein the substantially scattered light component and the substantially unscattered light component have a relative phase, and wherein the substantially unscattered component passes through a portion of the pupil; a variable phase shifting system located substantially at the pupil and configured to vary said relative phase by a select amount; and an image sensing system having: i) a detector array arranged substantially in the image plane and that senses an intensity of combined portions of the substantially scattered light component and the substantially unscattered light component after the relative phase is adjusted and after they have interfered with one another, and that generates in response thereto electronic signals that are—collectively representative of a raw image; and ii) a signal processor configured to process multiple raw images to form a processed image of the sample.