Systems, methods, and apparatus for differential phase contrast microscopy by transobjective differential epi-detection of forward scattered light are provided. In some embodiments, a microscope objective comprises: a housing with mounting threads at a second end； optical components defining an optical axis, comprising: an objective lens mounted at a first end, configured to collect light from a sample placed in a field of view, the plurality of optical components create a pupil plane at a first distance along the optical axis at which rays having the same angle of incidence on the objective lens converge at the same radial distance from the optical axis； a photodetector within the housing offset from the optical axis at a second distance along the optical axis； and another photodetector within the housing at second distance along the optical axis and offset from the optical axis in the opposite direction from the first photodetector.
