In one method, a display source aligned with an illumination prism assembly is displaced along a displacement axis to adjust the distance between the display source and a collimating prism assembly. The display source, the illumination prism assembly, and an illumination module are translationally moved in unison in a plane normal to the displacement axis. In another method, a component of an optical device is coupled to a mechanical assembly at a known orientation. The mechanical assembly has a test pattern at a known orientation. An image sensor is aligned with the test pattern, and the image sensor captures an image of the test pattern. The captured image is analyzed to determine an estimated orientation of the test pattern. An orientation parameter of the image sensor is adjusted based on a comparison between the known orientation of the test pattern and the estimated orientation of the test pattern.