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Five bleaching techniques for Agfa Gevaert Scientia 10E75 high-resolution plates were evaluated to determine resultant diffraction efficiency and SNR for identically recorded single-exposure holograms. We determined the optimum recording conditions for both single- and multiple-exposure bleached holograms using a cupric bromide bleach, judged to be the "best bleach." Data are presented for diffraction efficiency, SNR, and resolution of diffuse and focused-image holograms for both single- and multiple-exposure holograms, using a 1951 Air Force resolution chart as the object. Bleaching improved the diffraction efficiency of both types of holograms by up to 3 orders of magnitude. The SNR of diffuse holograms is degraded by bleaching, but that of the focused-image holograms is improved, while the resolution of both types is not affected by bleaching. Bleached multiple-exposure holograms are similar in response to single-exposure holograms except that their diffraction efficiencies are lower. The diffraction efficiency of bleached holograms decreases with age.

The holographic characteristics of Agfa-Gevaert Scientia 10E75 have been examined for multiple exposures. They include not only diffraction efficiency, but SNR and resolution as functions of number of exposures, time of development, and/or input modulation (rho'). The maximum diffraction efficiency, occurring at a density of 0.7, was observed to increase with increasing development time and decrease as the number of exposures increased. An approximately 10% decrease in maximum diffraction efficiency was observed for each successive reconstructed image of a multiple exposure hologram. Reconstructed noise was found to be fairly well represented by grain-noise considerations only for the region 0.1rho'0.4. Elsewhere noise is considerably different from grain-noise predictions. The SNR, at a density of 0.7, was observed to increase from 50 to 85 as the number of exposures increased from one to four. For postexposure or preexposure holograms the maximum signal-to-noise and resolution peaked near an input moduation of 0.4.

Two reprocessing techniques have been investigated that are capable of correcting the effects of nonoptimum optical density of photographic amplitude holograms recorded on Agfa-Gevaert type 10E75 plates. In some cases a reprocessed hologram will exhibit a diffraction efficiency even higher than that obtainable from a hologram exposed and processed to the optimum density. The SNR of the reprocessed holograms is much higher than that of the same holograms bleached with cupric bromide. In some cases the SNR approaches the optimum value for a properly exposed amplitude hologram. Subjective image quality and resolution of reprocessed hologram reconstructions appear to be no different than for normal single-development holograms. Repeated reprocessing is feasible and in some cases desirable as a means of increasing diffraction efficiency.