The diffraction efficiencies of surface relief gratings formed in Slavich PFG-01 silver halide emulsion have been studied in the frequency range 300–1200 grooves/mm in terms of relief depths and periods of the gratings. The relief depths generated in the gratings show a sudden decrease up to a certain frequency, then as light increase and finally decrease with increasing grating frequency for a symmetric algeometry of holographic recording.  Effect of grating period variation on the relief depth  of the phase gratings is found to be similar to the correlation of diffraction efficiency and grating aspect ratio. Diffraction efficiency response of a grating with a fixed groove frequency has also been investigated in terms of relief depths.