This question already has an answer here:
- Using a naked black hole as a mirror? 3 answers
I read that the image of the shadow taken by EHT is actually all the surfaces of the event horizon of M87 which extends to 2.6 schwarchild radius but wouldn't that also meant that we can also observe our galaxy clusters in that photonsphere which is the ring that is just beyond the 2.6 schwarchild radius, by the way I am not confused with the bright coffee mug stain like ring which extends out from 3 schwarchild radius which is supposed to be the falling matter around the blackhole. My question is can we see ourselves in the photonsphere?