Real-Time Holograms Beam Closer To Reality 79
sciencehabit writes "It's not quite the flickering blue projection of Princess Leia begging, 'Help me, Obi-Wan Kenobi, you're my only hope!' from the classic sci-fi movie Star Wars, but holographic projection has just beamed a bit closer to reality. Researchers in Arizona have devised a novel plastic film that can be used to generate holographic 3D images sent electronically from one location to another. The technology opens the door for everything from holographic surgery to movies that literally surround the viewer."
Re:Movies that literally surround the viewer? (Score:5, Informative)
Holograms aren't about walking around the image (although they can be), they're about true 3D; 3D that uses all the visual cues for depth rather than just one (or 2D plus one more cue).
Today's 3D movies aren't really 3D, they're stereoscopes. Your right eye sees a slightly different image than your left eye, and your brain combines them.
With a hologram, if your eye focuses on something close in the image, things farther away blur, and if your eye focuses on something farther away the foreground blurs. With stereoscopy, the camera does all the focusing, which is why some people get eyestrain with it -- the parallax tells the brain an object is s certain distance away, while its focusing tells the brain it's a different distance.
But as I said, TFA wasn't clear whether or not it's a true hologram, as it mentioned several cameras arrayed aroud the subject. With a hologram, you have one camera and two lasers.
I wish I could find a more technical FA about this, it looks fascinating.
Re:Every 2 seconds? (Score:3, Informative)
So this thing updates every 2 seconds [with a 100x one in the works]
Holy crap how did you misread that so bad? It's every 2 seconds now, which is more than 100 times quicker than it was two years ago. That's a huge improvement in a short period of time, and it is only going to get better. They need another order of magnitude (10 times) improvement to get it to a reasonable frame-rate of 30fps. Expect that in another year or so.
Also note that this is live video at 0.5fps. They could probably get that order of magnitude improvement if they weren't shooting live.
Re:yet another excuse... (Score:2, Informative)
No, it's better for the economy if he buys a 3D TV now. Followed by a "Real 3D" TV tomorrow, and a "Full 3D" after that. Or however they'll call the next few standards for 3D TV.
Re:Every 2 seconds? (Score:3, Informative)
Speaking w/ 30+ years of experience in holography, this is going to be really miserable to make practical. The computation involved is hideous for realistic scenes and the bandwidth is insane. If you want to get real time and something better than sick figures you have to heavily constrain the wavefront reconstruction.
A true hologram reconstructs the entire wavefront emanating from a scene, which gives it it's unique nature. Cut back the bandwidth and the realism or the viewing angle go to hell.
Re:Projection into the air (Score:1, Informative)
Of course you can make a laser beam hologram... with an IR laser split into a minimum of two beams more for varying degrees of shades (color values) then having it reflected in a symmetrical matrix with adjustable lenses.. I actually just made that up and googled it since it seemed so obvious. And yeah, someone has already done just that [physorg.com].
And.... this could actually make me a millionaire, extending on that it would be a piece of cake making a lightsaber (at least the visual effect of one).
Re:Refresh? (Score:5, Informative)
Here's what holograms are (Score:3, Informative)
This is a common misconception about holograms which has come about because of movie special effects.
A real hologram can show the illusion of something floating in front of you, but only so long as your gaze is directed *at* the hologram. Thus, a hologram "picture" hanging on the wall can only show an object while you're looking at the picture, but direct your gaze to the wall left or right and you see the wall. You can see a little bit around the object, but you can't walk around and see behind it because then you would be looking away from the hologram.
For a complete 3-d image you need a "band" of hologram that goes all around the room. Now, wherever you look you are looking into the hologram, and will see the image at the corresponding angle. The requirement to be looking at the hologram is still there - you can't look down through the object to the floor.
If the hologram covered every surface of the room you could have a the illusion of a complete 3-d representation of an object. In this case you could walk around it and view it from any angle, including from below and from above.
However, if another person were in the room with you, you could not see the object if they were between you and the wall. If they are opposite the image from you then you will see them, not the object. If you and they are at 90 degrees to the object, then you can see the object... but you can only walk around it to the point where the other person obscures your view of the wall.
Holograms don't cause light to change direction in mid air. It's just an optical effect that 'kinda reverses the focus in a way that tricks your eyes into thinking there's an object there.