  We developed realistic fully general relativistic computer code for
simulation of optical projection in a strong, spherically symmetric
gravitational field. Standard theoretical analysis of optical projection for an
observer in the vicinity of a Schwarzschild black hole is extended to black
hole spacetimes with a repulsive cosmological constant, i.e, Schwarzschild-de
Sitter spacetimes. Influence of the cosmological constant is investigated for
static observers and observers radially free-falling from static radius.
Simulation includes effects of gravitational lensing, multiple images, Doppler
and gravitational frequency shift, as well as the amplification of intensity.
The code generates images of static observers sky and a movie simulations for
radially free-falling observers. Techniques of parallel programming are applied
to get high performance and fast run of the simulation code.
