Pictures from space are always real, right?
if you don't agree,gather funds,hire engineers,train astronauts,go to space and prove me wrong.
OK. Just give me around 20 billion dollars and I will get started on it. 
You don´t need to do any of that, you can use a Weather Balloon (Some of the which are very cheap) and use a camera with it to take a photo.
If the Earth is flat why is there a horizon? We would be able to see up to the ends of earth with a weather balloon and a camera if this was true.
If the Earth is flat why are there timezones? Or why can we see farther from higher?
And what do you think of Arctic/Antarctica?