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The steps in reproducing evaporograph images are discussed. An analysis of signal and noise is given for different stages of the evaporograph process. The factors which limit the threshold sensitivity and resolving power of the evaporograph transducer are determined.

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In medicine, image -wise information (for example, x -ray image or thermogram) is obtained to diagnose diseases and to test the results of treatment.Being sometimes registered at low signal -to -noise values, it is not always sufficient to solve a specific problem.

The holographic method and experimental results for recording two -dimensional modulation transfer functions (MTF) of lenses are described. The conditions for hologram -filter recording are determined.The existence of optimum ratio between reference and object beam intensities, at which the results of measuring MTF match with those expected, will be demonstrated.The cause of formation of parasite intensity modulation in correlation distribution will be revealed and the way to eliminate it will be suggested. The requirements for granularity of the recording medium for hologram-filters are determined.It will be shown that the results of measuring the two-dimensional MTFs of lenses with symmetrical and non -symmetrical point spread functions by the holographic method are satisfactorily matching with the expected results and the evidence obtained through harmonic analysis.