Im not sure if you are aware but you can have fisheye lens that shows no curvature. Ofcourse its not a conspiracy that people think the earth is a ball. Its just looks like it is from space. And if you think someone can make such a widespread conspiracy I would suggest think again why such an effort? They could as well never go into space? Why going into space just to make more effort for themselfs to prove the earth is round. People had known its round using astronavigation techniques loooooong before the invention of propulsion. A matter of it being a concave or convex is a matter of the last 100 years when some experiments has shown that the earth is in fact concave, but its still round as astronavigation without any doubt has proven previously. Ofcourse the scientific lobby ignored the info about the experiments. Such things of hiding the stuff by scientists and rediscovering the theories is like a very common behaviour in the history of humanity. Concavity of the Earth destroy some theories and a lot of money is to lose and a lot less to gain by countertheory. Money and bribery does wonders sadly. Humanity is was and probably will be corrupted to the core.

Astronavigation has nothing to do with astronomy bullshit. First one is proven the latter is some mathematical guess game. Astronavigation is not guessing its a tool used in navigation at the sea. And if it would not work many naval discoveries and trade routes could be impossible or very hard to do. Possibly the Vikings were the first European to visit an America long before a Columb using a technique of Astronavigation. But it could propably be just one ship or a few of them that probably had not returned to tell the tale.