Good morning, ladies and gen-tlemen: It is my pleasure and privelege to welcome you to this first Seminar-in-Depth-of the Society of Photo-optical Instrumentation Engi-neers to be held in El Paso.

Modern lens design programs make it possible to thoroughly study alternative designs. A study of this type has been made on a Heliar and an aspheric Triplet. It is now becoming possible to define regions of solution and set standards of performance. We are now able to accurately predict performance of lenses and are beginning to tackle problems of setting tolerances. The use of aspheric surfaces has been retarded because of their expense. The large computer with modern data acquisition equipment may eventually also solve the aspheric generation problem.

In this day of the high speed computer with automatic optimizing programs, many optical designers are prone to forget that there are some simple approaches to the solution of optical design problems. One of these simple concepts is that of the concentric optical system. Some novel applications of this principle, to achieve diffraction limited performance for flying spot recording and readout are discussed, along with possible applications to a unique infrared optical system.

Since the introduction of digital computer techniques to lens design more than a decade ago, steady progress has been made in auto-mating, or partially automating, this conceptual process.

The need to assess the quality of an optical system arises first at the design stage when the designer is forced to make compromises in order to balance the influence of various image degrading parameters, and secondly, when the system is in the construction and assembly stage. Three methods of assessing the image quality of optical elements and electro-optical systems will be described in detail, along with numerous examples, analytical data and experimental results.

The quality of image forming optics may be determined in a number of ways from the purely psychological to the purely physical viewpoint. Sine Wave Testing is a physical method which completely specifies the optical response of an instrument. There are a number of other physical methods which can be shown to be completely equivalent. They are compared both for usefulness, ease, and accuracy of measurement. The implication of these considerations for system design and practical quality control is reviewed with emphasis of the use of Sine Wave Testing.

Some years ago, the author pointed out that an optical surface concentric with the image point may be used to alter or correct astigmatism without substantially affecting the other aberrations. This principle is employed in the design of a two element aplanatic corrector lens used with the Ritchey-Chretien form of Cassegrain optical system to correct the latter's residual field curvature and astigmatism. A review of the background optics is given.

A recent program reviewed for the optimum terrestial and space system utilization of over a dozen metals, ceramics and fused silica for reflective mirror optics. The relative suitability of the various materials and fabrication techniques for different applications have been summarized and criteria for the design of fabricated mirror blanks established.

The relationship between structural design and optical design is illustrated by showing how the combination of optical design and system performance specifications establish structural tolerances and design criteria for the detailed design of a 12 inch aperture, 92 inch focal 1 ength theodolite objective.

In the use of optics a method is presented for photographic determination of azimuth orientation in which human measurement errors are eliminated. Additionally, atmospheric turbulence effects are minimized and a short-term history of slab motion is obtained.

Promotion of education in the Photo-optics field has been one of the activities of SPIE for the past several years. Areas of optics that demand specialized training are listed. The requirements that must be met for establishing a Photooptics course or curriculum are given.