Aberration correction

A system comprising:

• a telescope configured to focus multi-spectral light into a beam;
• and
• a beamsplitter optically coupled to the telescope, wherein the beamsplitter includes an optical substrate with a first surface configured to receive a beam of multi-spectral light from the telescope, to reflect a first band of the multi-spectral light and to transmit a second band of the multi-spectral light through the optical substrate to be emitted from a second surface of the optical substrate opposite the first surface, wherein the second surface is a freeform surface, further comprising a first imaging sensor optically coupled to receive the first band reflected from the beamsplitter, and a second imaging sensor optically coupled to receive the second band transmitted through the beamsplitter, wherein the telescope is a catadioptric telescope, and wherein there are no non-axiosymmetric aberration components for correction between the beamsplitter and the second image sensor.