Method and test system for assessing the quality of a multi-channel micro- and/or subwavelength-optical projection unit

A method for assessing the quality of a multi-channel micro- and/or subwavelength-optical projection unit (28) is disclosed. The method comprises the following steps: At least a predefined portion of the optical projection unit (28) is illuminated so that an image is generated by at least two channels of the predefined portion of the multi-channel optical projection unit (28). At least one characteristic quantity is determined based on the analysis of the image, wherein a value of the characteristic quantity is associated with the quality of the projection unit (28), a characteristic feature of the projection unit (28), a defect of the projection unit (28) and/or a defect class of the projection unit (28). The quality of the projection unit (28) is assessed based on the at least one characteristic quantity. Moreover, a test system (10) for assessing the quality of a multi-channel micro- and/or subwavelengthoptical projection unit (28) and a computer program are disclosed