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We review the physical origins for possible visible images of thesupermassive black hole M87* in the galaxy M87 and SgrA* in the Milky WayGalaxy. The classical dark black hole shadow of the maximal size is visible inthe case of luminous background behind the black hole at the distance exceedingthe so-called photon spheres. The notably smaller dark shadow (dark silhouette)of the black hole event horizon is visible if the black hole is highlighted bythe inner parts of the luminous accreting matter inside the photon spheres. Thefirst image of the supermassive black hole M87 *, obtained by the Event HorizonTelescope collaboration, shows the lensed dark image of the southern hemisphereof the black hole event horizon globe, highlighted by accreting matter, whilethe classical black hole shadow is invisible at all. A size of the dark spot onthe Event Horizon Telescope (EHT) image agrees with a corresponding size of thedark event horizon silhouette in a thin accretion disk model in the case ofeither the high or moderate value of the black hole spin, $a\gtrsim0.75$.

Visible shapes of black holes M87* and SgrA*