Which form of entertainment introduced autostereoscopy (glasses-free 3D) into the mainstream?
That doesn’t really count…
Haven’t some live performances featured a hologram of a dead performer singing a song? I guess it could be done in a movie theatre also. I’d hate to think what the equipment would cost, and I believe most theatre owners are still grumbling about the 3-D projectors (that requires those glasses) they’ve already had their arms twisted into buying.
I’m not sure I get it, but maybe you mean something like the Nintendo 3DS?
According to Wikipedia, “The first experimental stereoscopic pairs of photographs were made in the early 1840s.”
I’m not sure that counts either. You had to look through a special lens in order to properly integrate the images.
I’m pretty sure the OP is a time traveler trying to get us to do his homework assignment.
No, they haven’t. Some performances have featured what they claim are holograms, but they aren’t. They aren’t even 3D. They’re just ordinary projections onto a screen: The only gimmick to them is that they use screens that are translucent, so you don’t notice them except where the image is projected.
Is the answer pop up books?
The answer is “video games”.
Lenticular 3D, which uses cylindrical lenses imposed on a picture to direct different images to the left eye and right eye, have been used since the 1940s.
The technology for lens-free, glasses-free 3D viewing was developed before the second world war. See here:
The Russians built a 3D cinemna for such films in 1941 (!). It was operating at least into the 1980s, and for al I know is still running. I don’t know why no one ever pursued this in the West. You’d think that the Disney imagineers would have had a go at it.
The basic technology, ion which different images are presented to right and left eyes, has been around since 1692 (although, AFAIK, not used for 3D viewing until the 20th century)
Incidentally, 3D movies go back to the 1920s. Originally the viewer looked through a rapidly rotating disc that was timed in sync with the projection on the screen, so that alternating frames were viewed by the right and left eye. It’s similar to the way some modern computer displays and some hoime 3D uses liquid cryustal “windows” to alternately block and unblock each eye. I imagine the 1920s version was prone to frequenmt failures. It wasn’t until Edwin Land invented Polaroid sheets that 3D got another chance in the cinema (The use of red-greem or red-blue anaglyphic glasses was a cheaper alternative for theaters out in the sticks that couldn’t afford the special polariozation-preserving screens and projectors.)
Friezes, about 3000 years ago.
I don’t think we have any proper glasses-free 3D that isn’t a physical object.
Certainly we do. Holograms, lenticular 3D, and the items in the post just before yours.
There are also some obscure optical effects that give an impression of 3D withot extra equipment.
Well, that and that it’s at a 45 degree angle, and you’re far enough away that you are missing binocular depth cues, so they can cheat by sticking with monocular ones.
Really, the only autostereoscopy I’m aware of is in devices like the 3Ds. Holograms and such are truly 3D, and don’t count. Now that the new 3Ds has head tracking, we’ve gone pretty far.
Without head tracking, autostereoscopy isn’t all that good. You have to find the perfect position. Plus, the primary form of 3D–movement-based parallax, isn’t present without it. That’s why even glasses-based 3D movies have to overdo it.
I know I’m typing – I can feel my finger hitting the keys. Why are you ignoring what I’ve written? Lenticular 3D isn’t holography. Yes, it does depend upon head position, as any binocular 3D system does. But the Russian theater I mention above accommodated quite a crowd.
While I don’t doubt you, I can’t imagine how such a theater would work. Were there restrictive headrests that kept your head (and thus eyes) in place? If not, then even minor wiggles of the head would destroy the illusion.
Not necessarily. Proper relaxation or tension of the eye muscles allows you to merge the two images without the equipment. It’s the same technique for seeing those hidden image 3D puzzles.
Don’t know – I’ve only read about it, and haven’t seen any diagrams. But the theaters were in operation for decades, so I assume there’s something to it.