Note the accompanying phenomena. Parts of the rotating accretion disk moving relative to a falling observer at speeds close to the speed of light shift toward the blue end of the spectrum due to the Doppler shift, while those moving away shift toward the red end. At the same time, relativistic beaming occurs: approaching parts brighten, while receding parts darken. As the observer approaches the black hole, the surrounding space shifts toward the blue end of the spectrum due to gravitational redshift. Ultimately, beaming optically shifts the space behind the observer in front of them, and the black hole appears to shrink.