Within the framework of this work, the numerical results of simulation and reconstruction of holographic images with different physical sizes of the object and observation areas are presented. Simple and practical approaches to relatively flexibility choice of physical areas (e. g., units of m²) in both planes are proposed. Algorithms are presented in the case when the dimensions of the plane of the object and observation coincide. Two-step scattering algorithms are presented for the simulation and reconstruction of holographic images with a relatively flexibility choice of the physical areas of the object plane and observation.