Abstract: A collector array for imaging comprises of a plurality of small concentrators having a hyperbolic cross section and a circular input and output aperture. Such an array is particularly suitable for use in conjunction with photoelectronic array-type detectors such as CCD's and with photographic film.

Abstract: A photographic contact printing system comprises a data base in which certain exposure parameters (e.g., spectral response, sensitivity, dot-growth factor, nominal exposure value and overlay factor) of a variety of different photosensitive recording elements are stored. Upon selection of any one of such recording elements by a printer operator, a microprocessor automatically controls an exposure source (e.g. an electrically energizable lamp) to provide a pre-programmed exposure of the selected recording element. During exposure of the recording element, a logic and control unit receives a time-varying signal representing the instantaneous spectral radiance of the exposure source. The LCU integrates the exposure produced by the source until the integrated exposure matches a nominal (or an adjusted nominal) value, at which time the exposure is terminated.