d. all of the water in-between including the shore and the base of the lighthouse visible in the viewfinder,
Speaking of which, why do lighthouses tend to be built on tall cliffs/rocks and tend to be tall towers? Doesn't make sense on flat earth.
So the confusion in your mind (implied but not established) about how perspective works somehow discredits a horizon greater than ten miles away, when it can only be three on a globe?
None of this perspective bullshit matters for a lighthouse. On flat earth you would have a direct line of sight to the light on top of the lighthouse whether it's placed right on the beach or 100 feet above sea level.
Seems like people hundreds of years ago figured out something that you still can't grasp today. Yes, I know, oven, rope, etc. Can I jump off a cliff next to a lighthouse?