I've acquired a new superpower • Hacker News Board

Re: I've acquired a new superpower

#331

Post by s4i » Fri, Jan 10, 2025, 9:38 PM UTC

Almost certainly a lot of the people saying they are ”crossing” their eyes are actually ”uncrossing” their eyes; focusing the eyes straighter than what would normally happen on the surface where the image is laid out.

This is also how the legendary ”Magic Eye” books were supposed to be viewed. Not by crossing the eyes.

Re: I've acquired a new superpower

#332

Post by Imnimo » Fri, Jan 10, 2025, 9:39 PM UTC

I can get the overlap to lock in, but the simmering effect is weak and difficult to pick out. Probably still faster than exhaustive search, but I don't feel like I'm at superpower level. Maybe my brain favors one eye more than the other? I know I have different glasses prescriptions for each eye.

Re: I've acquired a new superpower

#333

Post by labanimalster » Fri, Jan 10, 2025, 9:41 PM UTC

Learned it from Magic Eye books too! But using it for spot-the-difference is way more practical - saves so much time compared to staring at two pictures. Kind of feels like having X-ray vision for finding differences

Re: I've acquired a new superpower

#334

Post by abotsis » Fri, Jan 10, 2025, 9:43 PM UTC

I have strabismus and have always been good at these games. I wonder if it helps me for similar reasons? The examples on his page were pretty easy for me, though the universe one took maybe 45 seconds.

Re: I've acquired a new superpower

#335

Post by stavros » Fri, Jan 10, 2025, 9:43 PM UTC

claiir wrote: post #206

jeffhuys wrote: post #161

Earlier quoted context omitted.

To reduce eye strain, don’t cross your eyes, but relax them (so, the other way). Instantly clear and snaps together as if magnetic.

This is called “divergence” [1] and is less straining on your eyes than crossing them (“convergence” [2]) while being equally as effective spotting differences, even on video. It’s also what your eyes naturally do when you watch stereoscopic 3D with tinted glasses—the stereoscopic images are pulled out (divergence) not pushed in (convergence/cross-eyed). I’ve been doing this since I childhood. If you get good at it,…

The only problem with divergence is that you can't go too much farther out than the distance between your eyes, whereas convergence works for larger images as well.

Re: I've acquired a new superpower

#336

Post by xamuel » Fri, Jan 10, 2025, 9:44 PM UTC

BenjiWiebe wrote: post #328

xamuel wrote: post #244

Earlier quoted context omitted.

I wrote a paper about doing this using human eyes as the "repeating pattern" (either someone else's, or your own in a mirror): https://philpapers.org/archive/ALEDSK.pdf ...You can use this trick to make boring meetings or conversations mildly more amusing (but be careful not to look like a clown crossing your eyes). If you're an expert at this, you can even do it to your own hands. Hold both hands in front of you but…

If you're distant enough / the people are sitting close enough, you can stereogram two people's faces together. You usually only get fleeting moments of crispness when their heads are aligned correctly though.

Yep! If I knew someone IRL who was into this kind of stuff, I'd really love to experiment with this sort of thing and mirrors. Arrange so that you can stereogram your conversation partner's face with a mirror image of your own face (and that he can do the same with your face and a mirror image of his face). If anyone's in NYC and interested in these sorts of things, my email is in my HN profile "about".

Re: I've acquired a new superpower

#337

Post by rahulvarshneya » Fri, Jan 10, 2025, 9:47 PM UTC

This is just incredible!

Re: I've acquired a new superpower

#338

Post by PUSH_AX » Fri, Jan 10, 2025, 9:56 PM UTC

A ton of comments in here saying this is easy/old hat for them.

Well I'll be the one to say this blew my mind. somehow creating the third middle image, being able to relax my eyes and even scan around this composite image actually made me giggle out loud on my laptop, a very rare occurrence. Thank you to the author.

Re: I've acquired a new superpower

#339

Post by EVa5I7bHFq9mnYK » Fri, Jan 10, 2025, 9:57 PM UTC

Using this trick, I wrote a program for 3d plot visualization in the 80-s. It computed two projections of the plot, as if looked by left and right eye, and printed them side to side on the thermal printer. If you looked hard enough, you can bring the two pictures together and see a 3d picture!

Re: I've acquired a new superpower

#340

Post by Slow_Hand » Fri, Jan 10, 2025, 10:00 PM UTC

This trick is interesting to me as someone who mixes records. I (and mixers in general) have a lot of different tricks for making mono audio objects in the mix feel stereo or have a sense of width or depth.

Examples include:

1. Delaying the left or right channel by a few ms (Haas effect).

2. De-tuning one of the channels by a few cents

3. Boosting an EQ band on one channel, with a complimentary cut on the opposite channel.

...and many more.

These are usually very subtle changes that our stereoscopic ears have no problem detecting.

In any case, when we need to do some forensic searching for possible differences between two near-identical channels we'll invert the polarity on one channel and then sum them. The resulting delta sticks out like a sore thumb and highlights even then tiniest differences between the files.

So it's fascinating to discover that we can easily do something similar with our eyes to find the differences.