Wave optics aspects of image formation in strong gravitational fields (in a vicinity of a black hole’s horizon) are discussed. We consider two observers A and B placed (co) radially, r(A)<r(B) within Schwarzschild spacetime. The case of an image formation of an isotropic source of light placed at A in terms of lens arranged at B is analyzed. Emission (A) and propagation (AB) of the null geodesics results in the phase distribution (B), leading to the Airy’s rings pattern on the screen. This process is discussed in detail and illustrated. The comparison with the case of flat (Minkovski) spacetime is made. Research includes both static observers as well as observers freely falling toward an event horizon of a black hole.