A new method for the evaluation of the effects of the finite spatial resolution of the recording material on the reconstructed holographic image is presented. The method is based on substitution of the amplitude modulation transfer function (the square root of the modulation transfer function) of the recording material into the double Fresnel-Kirchhoff integral describing the complex amplitude of the reconstructed image. Numerical calculations have been carried out for holograms recorded in silver halide and thermoplastic-photoconductor materials. The contrast of the reconstructed image as a function of various recording parameters, such as the resolution limit and slope (in case of silver halides), and the center and width (in case of thermoplastics) of the amplitude modulation transfer function of the recording material, the object position and the reference beam angle has been computed. Thin holograms of microline objects have been studied in several recording geometries, including one with a tilted object plane.