Slashdot Mirror
Next Generation of Holographic Images
suman28 writes "Imagine being able to view an image from all sides and have it interact with you. Scenes or images pop-out at you and change on the fly and are viewable in full color. Best of all, you don't need head-gear or any wearable device to make this possible. They are generated by a computer with two cameras that track your eye movement and there is a transparent LCD screen between you and the display that makes the pictures come alive. Though it may be a while before this becomes part of our daily lives, it is interesting to see what the kind of research being done on this. "
That page has far too many ads.
Click here to read it without the annoying ads, but with all the pictures!
Traditional holograms are made from two beams of monochromatic light.
Using any old He-Ne laser you may have lying around the house, provide the light source.
The beam from the laser is divided into two paths. One beam is used to illuminate the object; the other is just a reference beam; you could even shine them while watching Baywatch or something as long as you can keep them fairly steady during the bouncing juggly scenes.
Also, try to find something in the kitchen or basement that has eight segments coated with a high-quality aluminum to provide for reflectivity in steps from 10% to 80% at 45 incidence (use a ruler or tape measure for quick measurements).
Oh, one more thing -- the laser should be on for about a half-hour to allow it to stabilize. If it's not warmed up enough after that time and doesn't seem to be very bright at all, peek into where the light comes out while it's on to check for any dust specs that may be impacting the light's exit from the device.
Bottom line -- (cos^2)(theta) dependencies rock!
Department of Physics and Atmospheric Science, Dalhousie University, Halifax, N.S., Canada, B3H 3J5
Even though everything is "behind glass", you are still seeing 3D. Afterall, the glass is transparent, it's not like the glass is "producing" the images...
Besides, driving down the street, you will want some *depth* perception. What's funky are those prescription windshields... Try being a passenger in one those cars. You almost need to be stoned/drunk to survive that without a migrain.
There are many different cues that contribute to our perception of depth: stereo, perspective, parallax, overlapping objects, shading and shadows and changes in accommodation and convergence of the eyes.
Those with one eye lack stereo (the strongest cue), but still have a decent amount of depth perception for surviving in the real world. It is only when attempting to use devices that rely soley on stereo to generate a pseudo-3D image that they have problems.
See this page for a more detailed discussion.
That's only the NYU system and the article says later that they're working on that. The MIT true-holograph system can produce the 3D images for multiple viewers, but is limited by the massive quantities of processing power needed. Meanwhile the NYU system runs on a pc but only gives the effect to one person, though:
"The group is also working on a system that would simultaneously provide 3-D views to multiple observers, such as a team of surgeons debating the best approach to a difficult procedure or a group of video game players competing on a shared monitor"
Sorry to be pedantic, but holograms are created with interference patterns using a laser on specially treated photographic materials.
What's referred to here are not, infact, holograms by definition. It's merely a 3D display technology.
(Holography is a hobby of mine...it's amazing how much fun a guy in his bathroom can have with a laser and some chemicals!).
-psyco