I'm not doing this with a camera. I did it with my eye.
If you put your eye next to your countertop and don't see the quarter becomes a half at 12 inches, you're lying.
Plain and simple.
Anyone can do it for themselves.
Now I’m being accused of lying.
I put my eye up to the plane of the table, level with it to the point that I CANNOT SEE ANY PART OF THE SURFACE. It is then, by definition, <= the level of the table surface, so that my angle of view is at worst upward, not downward.
The bottom of the coin DOES NOT DISAPPEAR.
It only disappears when I purposefully lower the level of my vision even further, at which point must be below the level of the surface.
This is not surprising, since what you describe is physically impossible unless light reflected from the bottom of the coin is somehow being obstructed from reaching my eye. Under any normal circuмstances that is not going to happen on a table with a coin an arm’s length away, and certainly not to the extent of obscuring a large part of it.