We need to test the imaging performance of the EUT after finishing the alignment of it. The method is placing the resolution test-target on the focal point of the collimator and illuminating the target by visible light. Then the visible light is becoming parallel light go through the EUT and imaging at focal plane on the CCD. By analysis the image we can calculate the resolution of the telescope. The test result indicated that the angular resolution of the EUT is 1.22″ (λ=570nm) which is very close to the resolution limit (1.20″). After the computation we conclude that the operation wavelength resolution is 0.32″

under our design request.