Fast tilt measurement based on optical block

•The tilt aberration detection principle changes from the measurement of the spot position change on the detector to the measurement of the energy change received by the detector.•By using the linear relationship between the change rate of light intensity and the tilt angle, the tilt aberration can be obtained quickly.•This method does not need to consider the size of the receiving spot, and can obtain a very concentrated optical signal on the focal plane, so the signal-to-noise ratio is high.•Using CCD or avalanche diode as the receiver, weak light detection can be realized.