Methods and devices are disclosed for aligning a lens assembly and a sensor assembly of an optical system during assembly of the optical system. For example, one method includes positioning the sensor assembly, having at least an image sensor, at the focal plane of the lens assembly and directing light through an alignment optic and lens assembly onto the image sensor. The method further includes producing multiple images from the light received through the lens assembly and alignment optic, the images having multiple alignment features based on the light received through the alignment optic, and the alignment features having multiple sections. The method then measures at least one performance indicator corresponding to each of multiple sections, and adjusts the position of the image sensor based on an optimization of the performance indicators, while the sensor assembly is being attached to the lens assembly.