How realistic are movie depictions of black holes, for example in the "Interstellar"?

The portrayal of the black hole "Gargantua" in the movie Interstellar  is somewhat realistic, in that they show the general morphology of these cosmic structures accurately. However, for aesthetic reasons, the movie producers removed one important aspect of the imaging to make the black hole more dramatic: the Doppler effect is switched off in the movie. In reality, the approaching side of the rotating accretion disk would appear brighter and hotter (blueish white), while the receding side would be dimmer and more red. Although the Interstellar production team consulted with physicists (most notably, Nobel-prize winner Kip Thorne) and based Gargantua on mathematical simulations, the movie ultimately showed a more artistic—brighter and more symmetric—rendering of the black hole. Furthermore, "Gargantua" is shown to have a razor-thin accretion disk, whereas astronomical observations of both Sgr A* and the M 87 black hole indicate that their accretion disks are much thicker, with a more donut-like appearance.

If you want to know more, follow this Twitter thread by the EHT member Sara Issaoun (@SaraIssaoun):

Let's unwrap another question we often get about the @ehtelescope 's #EHTblackhole image: Why doesn't the picture look like the black hole simulation in the movie Interstellar? Let's digest the differences one by one.  --- Continue here.