Rab, thanks for the photos. I don't see how it contradicts what I've said, it certainly is evidence of height differences making a huge difference on the perceived distance to the horizon however. 3m difference certainly makes the horizon look further away, technically an illusion of seeing further. From closer to sea level it looks like the earth curves away closer, but as your calculator shows, that's clearly not the case.
I can't see how you can claim that at all. Your originally past claimed
The horizon isn't where the earth curves away because you can't see that far away, while say, standing on a beach.
The first photograph showing the navigation beacon appearing to be on the visible horizon, or at least very close to it.
Scarborough, Beacon on Horizon The map locations of the camera and the beacon show that distance to be very close to 2.61 km.
The
Metabunk, Earth's Curve Horizon, Bulge, Drop, and Hidden Calculator shows that the expected distance to the horizon from a camera height of 0.54 m is 2.61 km.
When the camera height is raised to 3 m the horizon distance extends to 6.18 km. That is no "illusion", it fits quite well with what we see.
So I fail to see how you can see "technically an illusion of seeing further" - why an "illusion", it is simply reality.
Then you say "From closer to sea level it looks like the earth curves away closer, but as your calculator shows, that's clearly not the case."
Again what do you mean by "as your calculator shows, that's clearly not the case"?
It clearly is the case, because when the viewing point is 3 m high the tangent to the curve (the horizon) is 6.18 km away,
but when the viewing point is reduced to 0.54 m high the tangent to the curve (the horizon) is reduced to 2.61 km away.
Note, that while the 2.61 km distance to the beacon is quite accurately known, the heights are not claimed to be very accurate,
but are just intended to be a point very close to water level and as high as I could get at the location.
As far as I am concerned those photos certainly show that the distance to the horizon varies with elevation as expected on the globe.
You quite categorically stated that "The horizon isn't where the earth curves away because you can't see that far away" and that is what I claim is quite incorrect.
Those photos were taken with quite a long telephoto (1440 mm, 35 mm equiv), so show the beacon quite large, so I took a photo with a "normal" 50 mm setting to show that the beacon would be visible to the unaided eye.
In this photo the beacon is quite small, but still quite visible (and better before Photobucket "got at it").