  We study the influence of the tidal charge parameter of the braneworld models
onto some optical phenomena in rotating black hole spacetimes. The escape
photon cones are determined for special families of locally non-rotating,
circular geodetical and radially free falling observers. The silhouette of a
rotating black hole, the shape of an equatorial thin accretion disk and time
delay effect for direct and indirect images of a radiation hot spot orbiting
the black hole are given and classified in terms of the black hole rotational
and tidal parameters. It is shown that rising of negatively-valued tidal
parameter, with rotational parameter fixed, generally strenghtens the
relativistic effects and suppresses the rotation induced asymmetries in the
optical phenomena.

Astrophysics