Awesome optical illusion; the Shrinking Mill of Port Colborne

I have no idea how I never knew about this before, because Port Colborne isn’t far from here, but behold: the amazing Shrinking Mill of Port Colborne. Several videos, all showing you the same remarkable illusion so you know it’s not one guy playing a trick.

https://www.youtube.com/watch?v=hGJQPG_SInM&t=59s

That’s kind of neat, but easily explained. I certainly didn’t think it was a trick.

Sorta neat, looks like the perfect angle for the trees to frame the mill and make it look larger. Same reason the full moon looks so much larger near the horizon.

Although frequently stated, that’s not the reason for the Moon Illusion. If it were, there would be no Moon Illusion when the moon rises or sets over the unobstructed ocean horizon, but there is.

It’s complicated. The “relative size” phenomenon about the visual effect of nearby objects is certainly not universally accepted as the sole reason for the Moon Illusion, but it definitely plays an important role in it. As this article observes, our everyday experience trains our eye in the concept of converging-lines perspective, which applies to a featureless stretch of ocean or desert as well as to landscapes with prominent features. So the “relative size” effect is still operating even on an unobstructed ocean horizon.

Forget the moon. What’s going on here!?

Is that street going uphill, so there’s some kind of weird Atmosphere, or Earth Curvature, or Parallax something or other at play?

I guess it looks bigger while it’s framed within the trees and road.

ETA: by the way, the guy in the first video’s description of what will happen is awful. I didn’t even realize what was happening since he mentioned that it would “disappear”. I had to watch the 2nd video to figure it out.

I think what’s happening is that from the angle of view taken from the car near the beginning the mill blocks the line of sight. As the car gets closer, the road veers away, and it becomes obvious that the mill’s actually some distance off the side of the road. It doesn’t really look to me like it’s shrinking, but more as if it appears at first as if the road’s going to run right into it; when it becomes clear that isn’t so, the mill doesn’t take up as much mental space in the field of view, just because you’re no longer heading straight at it.

Same effect as using a paper-towel tube as a “telescope”.

I think this is the key. When you first look down the straight road you see the mill and the trees together in your view. From that particular perspective they look to be approximately the same size and same distance away.

But the trees are actually medium sized objects a medium distance away and the mill is a very large object a longer distance away. This affects how you perceive them as you drive down the road. When you’ve driven half the distance to the trees, they will appear to be twice the original size. But you’ve only driven a tenth of the distance to the mill by the same point so the mill will only look ten percent bigger. The effect of the mill only getting slightly larger in view while the trees around it get much larger in view makes it look like the mill is shrinking.

I just think it’s the assumption that the mill is right after the trees end, because there’s a noticeable end to the trees coming up and it would make sense that the mill was the reason the trees stopped. But it’s not - there’s just a large space of land with no trees in between.

Yes. And your mind thus expects the angular size of the mill to increase as you approach the end of the trees. But the mill is actually a surprisingly large building located a long way past the trees, so its angular size changes very little - which would be the case if it were of a normal size, nearby and shrinking.

It’s actually water (Lake Erie).

I found this site on Google Earth. The road (Lakeshore Road W) has a straight section about 500m long that points directly at the mill. The mill is another 1.6km past the place where the road bends left.

I wonder if the focal length of the camera lens is reinforcing the illusion, somehow.