  Ptychography is a lensless, computational imaging method that utilises
diffraction patterns to determine the amplitude and phase of an object. In
transmission ptychography, the diffraction patterns are recorded by a detector
positioned along the optical axis downstream of the object. The light scattered
at the highest diffraction angle carries information about the finest
structures of the object. We present a setup to simultaneously capture a signal
near the optical axis and a signal scattered at high diffraction angles.
Moreover, we present an algorithm based on a shifted angular spectrum method
and automatic differentiation that utilises this recorded signal. By jointly
reconstructing the object from the resulting low and high diffraction angle
images, the resolution of the reconstructed image is improved remarkably. The
effective numerical aperture of the compound sensor is determined by the
maximum diffraction angle captured by the off axis sensor.
