When auto stereograms 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. Still to this day my eyes will sometimes automatically snap into 'alternate' focus when viewing a repetitive pattern.
I've acquired a new superpower
61–70 of 583 posts
Re: I've acquired a new superpower
#62If you've done Magic Eyes, this is straightforward. Was able to get all 3 of the test images quickly. This is with focusing beyond the screen. Focusing in front of the screen is something I am unable to do, and not for want of effort. Also, your eyes might accidentally do this if looking at tiled patterns, e.g. wallpaper. Relative image size (e.g. view distance) is important.
As a kid, I got a Magic Eye book and learned to see it by crossing my eyes (ie, focusing in front of the screen). I thought it was pretty interesting when I realized that I was seeing all the images inverted ("peaks" were "valleys" and vice versa) due to the way I was focusing. Alas, I never was able to see the images "correctly".
Re: I've acquired a new superpower
#63Weird timing. I dunno why this works but I've been using it to see mice. You see, I noticed that I have a mouse problem in my garage. I figure if I've seen one mouse, there are probably more. So, I stood on some stairs in my garage and crossed my eyes to sort of blur the scene. It allowed me to catch movement more quickly and I was quickly watching multiple mice run around the edges of the area.
That seems like not the same thing though, right? You're not doing a diff on two images, you're just losing resolution so you can direct more attention to movement.
I think it's because our peripheral vision is able to observe movements faster.
Re: I've acquired a new superpower
#64If you've done Magic Eyes, this is straightforward. Was able to get all 3 of the test images quickly. This is with focusing beyond the screen. Focusing in front of the screen is something I am unable to do, and not for want of effort. Also, your eyes might accidentally do this if looking at tiled patterns, e.g. wallpaper. Relative image size (e.g. view distance) is important.
As a kid, I got a Magic Eye book and learned to see it by crossing my eyes (ie, focusing in front of the screen). I thought it was pretty interesting when I realized that I was seeing all the images inverted ("peaks" were "valleys" and vice versa) due to the way I was focusing. Alas, I never was able to see the images "correctly".
Instead of crossing your eyes to focus in front of the image, you have to uncross them and focus on something behind the image. Put your finger about six inches in front of your face and then look at the horizon. If the horizon is in focus you should see two fingers.
Re: I've acquired a new superpower
#65At a local bar they had a game machine, and if you got a high score on any of the games, your tab for the evening was free. One of the games was a "spot the differences" between two pictures with an ever decreasing timer for each round. Using this trick I was able to easily surpass the high score, and garner a crowd watching me perform this mind numbing feat. Probably my peak fame right there.
I can't overlap the images to save my life - they get like halfway there and that's it...
Re: I've acquired a new superpower
#66Earlier quoted context omitted.
As a kid, I got a Magic Eye book and learned to see it by crossing my eyes (ie, focusing in front of the screen). I thought it was pretty interesting when I realized that I was seeing all the images inverted ("peaks" were "valleys" and vice versa) due to the way I was focusing. Alas, I never was able to see the images "correctly".
Instead of crossing your eyes to focus in front of the image, you have to uncross them and focus on something behind the image. Put your finger about six inches in front of your face and then look at the horizon. If the horizon is in focus you should see two fingers.
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Re: I've acquired a new superpower
#67Wait, that's not crossing your eyes, it's uncrossing them. Ordinarily if you look at something nearby, your eyes aim at a common spot. But when viewing a stereogram, you need to convince your eyes to aim at a spot more distant than the subject. This is easy with practice, however IMHO it helps to be significantly nearsighted. Then you simply take off your glasses, and can look at something nearby with infinity focus,…
For spot-the-difference, crossing your eyes is more effective and easier to "dial in" than uncrossing them. You're essentially making each eye look at the opposite image. If you try uncrossing, then you need to make sure the images are at the exact correct distance to cause them to overlap with that technique, because you can only uncross your eyes enough to look straight ahead.
It’s a good thing that properly designed stereograms take this into account and don’t require you to uncross your eyes past that point.
Re: I've acquired a new superpower
#68I discovered this trick independently about a decade ago, to use cross-eyed viewing to easily spot differences between two similar images. Like you said, the parts that mismatch appear to shimmer and be unstable, making them obvious.
However, I feel eye strain from doing it, so I prefer other methods. 99% of the time, I do https://en.wikipedia.org/wiki/Blink_comparator instead, just switching between two images with zero flicker and zero displacement offset. Also with both eyes, it's easier to spot certain kinds of subtle differences like color shifts, JPEG-like compression artifacts, tiny differences in antialiased renderings, etc.
One benefit of the cross-eyed method, though, is that you can difference videos. But the use case for that is rarer than differencing images.
Re: I've acquired a new superpower
#69If you've done Magic Eyes, this is straightforward. Was able to get all 3 of the test images quickly. This is with focusing beyond the screen. Focusing in front of the screen is something I am unable to do, and not for want of effort. Also, your eyes might accidentally do this if looking at tiled patterns, e.g. wallpaper. Relative image size (e.g. view distance) is important.
I can get the images to merge but the differences don't stand out.
Re: I've acquired a new superpower
#70At a local bar they had a game machine, and if you got a high score on any of the games, your tab for the evening was free. One of the games was a "spot the differences" between two pictures with an ever decreasing timer for each round. Using this trick I was able to easily surpass the high score, and garner a crowd watching me perform this mind numbing feat. Probably my peak fame right there.
I can't overlap the images to save my life - they get like halfway there and that's it...
Try on mobile, it's easier if the images are smaller.