Lens Fabrication, Tolerances, Procurement, Inspection, and Mounting

A complete set of specifications and standards covers every aspect in detail of the optical manufacturing process, from drawings to fabrication and inspection. These specifications and standards are important for manufacturers to maintain high and stable qualities for their products. However, for optical-component users, they appear to have too many details and are not very relevant. For example, users very rarely need to inspect the quality of the glass used in their lenses against the specifications; they may occasionally measure the performance of their lens, such as the focal length or the image resolution. Therefore, this chapter mainly discusses the principles of specifications and standards, not the manufacturing details. Manufacturers will usually take care of the details of specifications and standards for users if the latter can convey their needs to the former.