Random-Dot Stereogram QSL Card
The random-dot stereogram has been a popular art curiosity for a long time. You might know it as "The Magic Eye."
You can make your own random-dot stereogram QSL card by using Do It Your Self web sites like:
https://www.ime.usp.br/~otuyama/stereogram/basic/index.html
My QSL Card is attached.
Can you see it?


The size of the card you are viewing will affect the ease of viewing. Most people can view them without special viewing glasses.
You have to fuse the 2 dots at the bottom, so that you can see 3 dots.
The best way is not to cross your eyes but look at infinity. Not being able to see it straight away is what makes it interesting. It is like steganography. Visual crypto.
Viewing instructions for stereograms are in Wikipedia: https://en.wikipedia.org/wiki/Random_dot_stereogram
There are 2 viewing methods, Divergent and Convergent. My QSL card should be viewed with the Divergent method. If you use the Convergent eye method (Crossed eyes) all the depth information will come out backwards. Using the Divergent method, the letters will appear to float above the background.
You must focus on a distant object and after a few seconds you will see the depth of the image.
If you then try to refocus on the image it might disappear. This is the technique that fighter pilots use to stay focused on infinity to spot other aircraft. You have to relax and let the image come to you.
It is a cross correlation of the information in your brain.
The size of the stereogram might have to be adjusted if you are viewing it on a large screen display.
Paul, W0RW
| W6BP | 2022-05-08 | |
|---|---|---|
| Random-Dot Stereogram QSL Card | ||
| Hilarity will ensue when you try to give one of these to an ARRL QSL-card checker for award credit! | ||
| K5TED | 2022-05-08 | |
|---|---|---|
| Re: Random-Dot Stereogram QSL Card | ||
| Even cooler: If you convert the phonetics into Incan caricatures then no one at tall will ever be able to decipher your call. Not even Incan caricature interpreters, since radio was not a thing back then. Reply to a comment by : W0WCA on 2022-05-03 Paul: This is really cool stuff but I think that the stereo part says that one must be able to see out of both eyes to see it. We one eyed wonders are never going to see it - right? | ||
| W0RW | 2022-05-04 | |
|---|---|---|
| Re: Random-Dot Stereogram QSL Card | ||
| N4KZ, Sorry you can't see the stereo image. It can be hard if the spacing is too wide. Try a smaller image, It is a learned skill. Bill, If you only have vision in one eye, there will be no stereo, Sorry. Both eyes must be able to focus the image too. Paul w0rw Reply to a comment by : N4KZ on 2022-05-04 I've been on the air for a long time. Instead of having thousands of cards, as I do now, if they all used this method of design, my card collection might consist of a dozen or so. Way too much effort to view the card. Sorry to be negative. 73, N4KZ | ||
| N4KZ | 2022-05-04 | |
|---|---|---|
| Random-Dot Stereogram QSL Card | ||
| I've been on the air for a long time. Instead of having thousands of cards, as I do now, if they all used this method of design, my card collection might consist of a dozen or so. Way too much effort to view the card. Sorry to be negative. 73, N4KZ | ||
| W0WCA | 2022-05-03 | |
|---|---|---|
| Random-Dot Stereogram QSL Card | ||
| Paul: This is really cool stuff but I think that the stereo part says that one must be able to see out of both eyes to see it. We one eyed wonders are never going to see it - right? | ||