If you cross your eyes and look at the routes as if it were a single stereoscopic image overlaying one route on top of each other, the misplaced hold jumps out at you immediately.
There's a challenge where you see words like "RED BLUE YELLOW GREEN PURPLE", but they are written in color different to their name. You are challenged to say the color of the text and not read the word out loud.
Intentionally defocusing your eyes makes that challenge trivial.
I don't understand how this works. If I cross my eyes, the images become extremely blurry. I can't even tell if they are precisely overlapping or not, let alone see if one of the holds is out of place.
That needs training, took me quite some time to learn this in the early 90s when the Magic Eye books [1] came out and autostereograms could be found in many newspapers. I personally also never learned to cross my eyes, I instead make them look parallel, see the diagram in [2]. Once you have learned it, it is hard to unlearn, to the point that once in a while my eyes and brain will snap onto repetitive patterns like grid paper or just text without any intention to do so.
>once in a while my eyes and brain will snap onto repetitive patterns like grid paper or just text without any intention to do so.
When autostereograms were all the rage in the late 80's I had a program on my Mac Plus that let me make/edit them and I used to edit for hours WHILE looking at them in 3D. Then one time I was walking down a hallway with a repetitive wallpaper pattern, my eyes did the thing, the entire hallway appeared to shift in front of me, and I stumbled and fell.
> Once you have learned it, it is hard to unlearn, to the point that once in a while my eyes and brain will snap onto repetitive patterns like grid paper or just text without any intention to do so.
Rare that I meet someone else that does this. I learned how to do magic eye puzzles as a young child, I think my first was in a magazine and I ‘solved’ it the standard way of placing it close to your nose then slowly pulling back. Before long I could just do it on command and as an adult I find myself doing it all the time, often unconsciously. Makes spot the difference puzzles trivial, that’s for sure
Good idea. I just tried that on the first image of the whole route (after zooming in a bit) and the misplaced hold looks like it's floating in space away from the wall.
I tried this, and while I didn't have any difficulty establishing a stereoscopic view it didn't jump out for me at all. I perceived the blue line floating on top of the problem handhold, but the handhold seemed to be on the same plane as all the others. Knowing it was the problem one, I could use the stereoscopic view to see it, but without already knowing I don't think it would be apparent.
This is odd to me since I've successfully used stereoscopy in the past to find small differences. For some reason, with this image, rather than causing a change in perceived z-level, my eyes fight for dominance and my left ends up winning.
It took me a little while, because that blue line is definitely a distraction. But once the other holds all settled down to being properly in the plane and sharply focused, and I ignored the blue line, the misplaced one was clearly above the plane.
I usually find it easier to relax my eyes (focus too far rather than too close), and so the opposite occurred - most of the holds appeared to float in a single plane (slightly wavy perhaps due to lighting differences), while the incorrect hold was sunk further back.
Took me a bit to realize the last photo has it correctly, and to stop trying to find the discrepancy there. Looking at only the first image it pops out to me because the wrong one is floating closer to my eyes than the rest.
