This is the most accurate depiction of a Black Hole made in 1979. Long before the Event Horizon Telescope, there was an astrophysicist named Jean-Pierre Luminet. In 1978, he already gave us what could be thought of as the very first image of a black hole's event horizon. It is not an actual photo, but being skilled in the field of mathematics, Luminet performed, what was the first ever computer simulation on visualizing an image closest to that of a black hole.
Equipped with a 1960's punch card IBM 7040 computer, Luminet spent many painful hours plotting the points with his hands equipped with nothing more than link and negative paper. That fuzzy image (seen above) shows what a flat dics of material falling into a black hole might look like if we were close enough to see it. He plotted all the points as per the location where brightness was more or less and then took the image and turned it negative once again resulting in the first ever most accurate depiction of a Black Hole yet!
The image is actually of the region where the material which is falling into the Black Hole is in an orbit around it and glows due to collisions.
"It doesn't look flat, because the intense gravity of the black hole is bending light around it. "indeed the gravitational field curves the light rays near the black hole so much that the rear part of the disc is 'revealed'" Luminet explained.
This image still holds the 1st position for being the most accurate surpassing even the one shown in Interstellar, because the Interstellar Black Hole was also made a little beautiful to give a special cinematic experience!