My time has come!
The above stereographic image is for cross-eyed viewing (most stereograms are wall-eyed, so you may need to put your finger in front of your screen until this one comes into focus)
This is an image of Honolulu, Hawaii, published by NASA. Note Diamond Head (the volcanic crater) in the south.
Here are some other stereopairs published by JPL:
Wheeler Ridge, California
Mount Saint Helens
Salt Lake Valley, Utah
Wellington, New Zealand
I can still view these, but it’s much much harder for me.
I don’t know why parallel isn’t the default.
It varies per person. I for one can’t view wall-eyed, only cross-eyed.
Same here basically, cross-eyed viewing is super easy for me but I have to work for minutes to perform wall-eyed viewing. I was really excited to see a post with cross-eyed stereograms.
I have to exert constant effort to cross my eyes, don’t you?
Also can’t do parallel, only cross view. I only have to use effort for the first few seconds, as soon as the two images are aligned, my focus snaps to it and I can relax and keep the focus without having to think about it.
It does cause some mild strain if I’m doing it for too long (like going through a book of these), but if I’m cross-eyed for a just a couple of minutes its no problem.
Huh. For me I can very easily wall-eye, I just let my focus drift. Going cross-eyed requires serious and constant strain, and doing the trick with my finger in front of the screen doesn’t work – I can get the dots aligned but if I try to focus on the screen or move my finger I lose it instantly.
What is parallel ?
Parallel are the ones where you put the image between you and your point of focus, instead of your point of focus being between you and the image.
Lots of people can really easily go cross-eyed and look at these with no practice whatsoever. Fewer people can do the parallel kind with no practice or with the amount of practice they’ve already done.
Cross eyed is so much more uncomfortable. It also looks smaller than parallel to me.