The problem of a pinhole camera is discussed using the theory of partial coherence. In particular the incoherent limit shows that the minimum object or image distances should be greater than one far field distance of the pinhole. The theoretical resolution limit is inversely proportional to the product of the pinhole size and the number of pinhole far field distances to the object plane. However, consideration of the three dimensional intensity distribution of the camera impulse response shows that the maximum resolution is achieved at one third of a far field distance. The optimum pinhole size is also discussed. In the coherent limit it is shown that the imaging system is inherently non-linear, and that the speckling deteriorates the image. Experimental results demonstrating these conclusions are shown.
The extension of the dynamic range of the vidicon to 104 as the result of work conducted at the Lincoln Laboratory suggested the use of this sensor for information retrieval of data recorded on photographic film, in this particular application, microdensitometry is used to read-out radiometric, spatial and spectral data recorded on film. Conventional microdensitometers utilize microscope optics and photomultipliers. A new approach to microdensitometry is proposed in which the microscope optics are replaced with longer focal length projection optics and a vidicon tube replaces the photomultiplier. An experimental imaging-microdensitometer was built and its performance will be discussed.
This paper will describe the optical design considerations associated with the development of the first known use of the laser in a production shop. One of the problems encountered in taking the laser out of the laboratory and into the shop is to provide a suitable viewing system (unless the application is simple enough to allow automatic control. It can be shown that closed circuit television offers many advantages over alternate approaches. For monitoring the laser operation the optical design criteria for operation and safety will be developed, and the television system which was used on the production laser machine will be described in detail.
This paper discusses some applications of the smear camera, one of the primary tools used to measure the velocity of rapid reaction fronts in an explosive or detonation reaction. Solid cylindrical explosive charges are normally initiated at a small area on the end of the axis. Due to the nature of propagation of a reaction front, the optical records, normally obtained from the periphery of a charge, are distorted and do not give a true measure of the front's velocity. For accurate measurement, long charges are ordinarily used and only a small portion of the total smear record is used to obtain the true velocity. A transformation equation has been derived whereby the data from smear camera records of the peripheral detonation of a short (L/D of 2.5) tetryl charge can be interpreted to obtain a detonation velocity measurement. The results are in excellent agreement with the values measured along the axis as well as with those published in the literature.
The concept, background and objectives of the Mobile Cinetheodolite Mount i(MCM) are presented; and design, development, construction and operation are explained. The electronic circuitry is described in detail. The principal technical features of the MCM and the general layout of a typical site are discussed and depicted.