Circling a Black Hole at its Photon Sphere . ... One particularly interesting place near a black hole is its photon sphere, where photons can orbit in circles, a sphere 50 percent further out than the event horizon. Were you to look out from the photon sphere of a black hole , half of the sky would appear completely black, half of the sky would appear unusually bright, and the back of your head would appear across the middle. ... Disclosure: Video creator Robert Nemiroff is an editor for APOD.) ...