Please inform me on how to us perspective correctly.
Well first, understand what perspective
is.
It is:
"The art of representing three-dimensional objects on a two-dimensional surface so as to give the right impression of their height, width, depth, and position in relation to each other."
Basically, when things get further away they look smaller.
Clearly in real life these tracks are parallel but the further ones away look like they are closer than the nearer ones. And the vanishing point is
"the point at which receding parallel lines viewed in perspective
appear to converge"
Note the emphasis. Appear to. They don't really converge.
And if object A goes behind object B from your perspective then you can no longer see object B (assuming A is opaque).
What this means is if I have a clear line of sight to an object then I will be able to see it IF
a) My eyesight is good enough
b) Atmospheric conditions allow.
So Perspective cannot:
Explain sunset, if the sun is above a flat plane then I will be able to see it at all times unless something is in between me and the sun which, if I'm looking out to sea, there isn't. The sun would just get smaller and bigger.
Even if you accept that the sun is a spotlight (which creates a load of other problems), the sun would not slowly sink below the horizon.
Explain long shadows at sunset or shadows cast upwards, clouds being lit from below. Shadows are cast because a light source hits an object, the angle and length of the shadow depends on the physical relationship between the object and light source. Long shadows at sunset prove that the light source (the sun) is physically on the horizon and sinking behind it. Or it is appearing to be which means the light is bending. And yes, light can bend but you'd have to show what atmospheric affect is causing a sun 3000 miles above the earth to appear as if it on the horizon.
Ships disappearing hull first as it sails away from us at sea. The ship will get smaller but it won't slowly sink hull first behind the sea unless it is going over a curve.
On a flat plane I can see things so long as there is a clear line of sight between me and the object:
But on a curve I can't. Here I can only see the person's head, as the person goes further behind the hill he will disappear starting at the bottom:
And THAT is why the sun sets and boats disappear hull first, if we lived on a flat earth that would not happen.
But Perspective can:
Explain crepuscular rays.
https://physics.stackexchange.com/questions/263653/flat-earthers-claim-crepuscular-rays-implies-the-sun-is-closeClaiming that crepuscular rays show a close sun is as silly as claiming that the photo above of the rail tracks show that the tracks originate from a point not that far away.