This is the same useless explanation that literally everybody gives about holograms, lots of blabla about lasers, reference beams, beamsplitters and interference, yet they completely skip about *why* any of this actually produces a hologram. What is actually captured on the photographic plate? How is the phase encoded? How do you end up with a 3D image? How can you encode 3D information on a 2D plate?
You need to read more as I do too however I have the same question. My question is how to create 180 degree illusion of required image, and how many image captures would it take? Then after all said is the application of images to glass plate.....my head hurts!!!
@@sub-vibes Thanks. I guess that might be a long technical explanation, but Recording them in a 2d plate is the key tech in holography isn't it? That's the hard part and nobody tries to explain it.
Yeah there was something about this that was bugging me but I couldn't figure it out. In my defense, it's Friday night, and wine and weed is legal here.
What he says is correct, but the concept of phase containing the relative distance to the object is very obscure to the average person. In addition, any small location on the hologram film captures the entire image, where a photo captures only a part of the image on each part of the film. ... Having made holograms (literally in my basement), the really detailed "WHY" a hologram does what it does is not simple to understand, much less explain in words. ... ... How the simplest "Transmission Hologram" is made ... ... The laser beam is split into two beams with something like a partly silvered mirror. Each beam is spread out, using a simple lens, to form a wider cone-shaped beam more like flashlight's beam instead of just a dot. One beam shines on the whole film and is called a "reference beam". The other "Object beam" shines (by using mirrors to direct it) onto the object being "photographed". The laser light reflected off the object goes in all directions, as usual, but the light reflected from the object which travels toward the film combines with the reference beam to form the interference pattern on the film. Both of these two beams hit the film at the same time. ... The reason two beams are needed is as follows. Light is a wave of extremely high frequency. This is just like the AC coming out of household outlets, but light is varying about seven zillion times faster. It varies in a sine wave like intensity at this incredible rate. Simply shining light at a camera's surface will only result in a average amount of light energy being registered. This is how an ordinary photograph works. If, however, we add another beam of the same frequency (from the same laser) we get interference patterns. Interference patterns, also called fringes, are standing waves. Where the two ever-changing waves arrive always peak-to-peak (and trough-to-trough) they add to form more light and expose the film the most. Where the two waves meet trough-to-peek (and peak-to-trough) they subtract, or partly cancel, and the film is exposed less. In other words, the distance between the object and the screen is recorded on the film due to the fact that the reference beam creates these interference patterns. For parts of the object that is further from the film, these interference patterns are at a different depth within the film. All this goes on at a scale (resolution) on the order of fractions of a wavelength of light. Ordinary film only requires a resolution on the order of the ability of the eye to see the individual picture dots (pixels). ... However, it must be understood that this is a very, very, *VERY* complex three dimensional interference pattern within the film's emulsion. Because the film has thickness, there are interference 'patterns' created through the depth of the emulsion as well as across the surface dimensions. It is very difficult to describe in terms of the two simplest waves forming an interference pattern of just rings. If you have seen any kind of interference rings or patterns, you should realize that even though the light waves are going through their full cycles of extremely high frequency, these interference patterns are stationary. They are called standing waves. Because these patterns don't move as the light waves vary through their AC cycles, they expose the film in a stationary pattern. Also because the emulsion has thickness, these interference patterns can be different as you move through the thickness of the film, as well as around the surface (as in an ordinary photo). ... Side Notes:If you understand how standing waves are produced on a radio transmission line, this is the same principle, only in three dimensions instead of just one. If you understand the mixing of frequencies in a radio receiver you have a very little understanding how interference between two waves can preserve the information in one wave. ... After the film is developed and bleached (remove the silver oxides) to make it look clear, it can be viewed. To view the image the laser beam is spread out again with a lens and shined on the film from the same direction as the original Reference Beam. This film is now just like a "window" though which you see the object in the same position it was when the film was exposed. ... You may think of the hologram film as having zillions of really small, strangely shaped and complex prisms that refract (bend) the laser's light. They refract the light from the viewing laser into a form that duplicates the way light left the original object. Also, because they are prisms and prisms spread the colors in slightly different directions, you must use the correct wavelength of light to reconstruct the image correctly; though in my experience a close color looks pretty much the same. This may not help, but if you viewed a hologram of the simple interference rings from two split beams aimed at the film, you would see a single spot of light representing the "object beam". ... Once again, the hologram produces light that leaves the hologram in the very same way it left the original object (and passed "thought" the window formed by the film). As your eye moves around the window's area, you see light in the same way that it actually left the object and traveled in that direction to the film. Since, at any one time, an eye only looks through a small part of this film window, this means that every location on the hologram film has a *complete image* of the object as viewed from that single location. THEREFORE, your two eyes, located at different locations and looking toward the film window, receive light in the same way they would form the actual object and you see it in 3-D. ... P.S. Yes, it is possible to make a hologram image that "floats" in front of the film. This is done as a hologram of a hologram to get the image on the other side of the film. However, in this case, the film must always be behind the floating image. Light through the film must meet your eye. It is a "virtual window" behind the image. A complete ring of film is required for you to walk around such a floating image along with light from a single laser coming from all around the outside and shining inward toward the center. ... P.P.S. Another amazing aspect of these "Transmission Holograms" is that if you shine a laser dot onto the hologram in the reverse direction from the original reference beam, you get a *complete image* of the object projected on a screen located where the object had been. This is *with NO lens*.. The image will be seen from the perspective of the point on the film where you would have looked at the original object when you exposed the film. As you move the laser dot around the film, the projected image changes perspective (rotates) to match that location on the film. I saw this demonstrated in a hologram talk and duplicated it myself. Very COOL! ... P.P.P.S. There are white light Holograms (which has all wavelengths/colors) and they use a nifty trick to do that, which I won't go into here. ... P.P.P.P.S. The "hologram" is the film, not the image it produces -- ScienceAdvisorSteve
Observ45er I'm studying quantum mechanics right now and I think that I understood the biggest part of it. Have I got it the following correctly? (I'd actually really want to know if I get it right or wrong... :) so please answer haha :P -What everyone thinks is the hologram is actually not the hologram. The hologram is the film, not the projection we see in movies. How it is made: -Because destructive interference occurs when the reference beam and the beam of light reflecting of the object are not in fase; only the one's in fase reach the film (hologram). -The fotons of the light with this frequency "carve" a very specific pattern/hole in the film while going through it, so that once that "hole" is made only light of that specific wavelength and fase can go through the film. -Meaning that when light with the same properties as the first laser is shined upon the hologram, only the waves with the same frequency as those that were reflected from the image, get through the film. Making that for someone looking through the hologram on the otherside, only these light 'waves' reach his eye. -Making his brain translate these to an image which is exactly that of the original object viewed from the position of the "hole" in the hologram. And thus the man is tricked by his brain into thinking that there is an object that is identical to the original object. How the image comes alive (not yet moving!) like we see in star wars etc. : -You can do it in various ways. 1.) By looking through it from the back and shinging a identical light source upon the front. So the light reaching (getting through the film) your eyes on that spot is identical to the light that would reach your eyes if there was no film and the object was just placed on the spot, where you're tricked into thinking that it stands when looking through the hologram. (The non-common known way) or 2.) -By putting you firstly made hologram in front and shining an identical light source upon it so that only the light containing the visualisation of the object pass throught it. (With 'light containing.... etc' I mean the ones that would reach your eye in nr. 1 and make you 'see' the image) -Then you'd make these specific lightbeams shine upon the back of another hologram, kind of identical to the first (this I do not understand completely...) which breaks the light into different colours just like prisms do. The colours into which it breaks are the ones that were reflected of the objected while making the first hologram. -To see the image of the object 'float' in the air, you'd have to stand 'last in line', facing the second hologram (the one with the prisms). When you move your head into the "zone" of shatterd light, it reaches your eyes and you see the image 'float' in front of you. -If you'd make a big circle with 2 rings of this construction (outer ring 1st hologram etc.), the destructive interference of all these shattered light beams would leave only standing harmonic waves in the centre, which would create an exact representation of the original object. And you'd be able to walk around it seeing all it's different sides. So this is what I understood from it... The 2 majors things I don't quite comprehend is the making of the prism-like-hologram, and the creation of the image by the standing waves in the centre of such a 'circle'... (I'm thinking it somehow works like blackbody radiation etc...) I hope hearing from you again! Best comment ever, making it really clear! :))
@103923042998206097090 You have a good understanding. There are some parts that are difficult to understand and they are difficult to explain in words, but your description holds a good explanation. The two beams create a standing waver pattern in the film. After the film is developed, that pattern will re-create the original light coming to your eyes.
Indeed. Everyone can understand the laser interference. Yet the big thing appears to happen at the film structure, because you can reproduce the image with normal light. Aint no genius explains that !
9-years later I went to CES 2023...I saw "fish" swimming in an "aquarium"....it BLEW ME AWAY! Can you do another Hologram one with what's going on today? Thanks Bro!
I agree with you, the way it's done now isn't particularly great and doesn't really add anything. Whether using holograms will bring a whole new experience to films I don't know, but it certainly would be a great way of video chatting for example.
The Hobbit and the Life of Pi... oh my god I feel old right now. They came out near when I graduated high school. Actually The Hobbits part 1 was where I took my high school sweet heart for our first big date, not in 3D but it was opening night. And after some reflection I realized that year I graduated (2014) we watched the Life of Pi in English class, we'd only just stared trying to be friends again... good times 😆
In Logans Run they made holograms of the actor's head on film. As they rotated the film in a cylinder, the head also rotated, but he was also speaking.
Gr8 gratutude finally in tune with reality to context to science in media outlet and educational entertainment. Least I have happiness to know also I have a lecturer on BritLab thank you sir, missed out on elders of youth lecture since I got envied in university.
Would love to see you guys play around with one of our LitiHolo Hologram Kits, so that you can make your own holograms. Let me know if you are interested.
So, by using an array of satellites, equipped with radiological, and electromagnetic frequency (and other) detecting cameras, all linked remotely to a server, and a display being a series of different colored lasers, projected on to a smoky background, inside a glass bubble... you could have a real time, 3D view of an entire planet, with the ability to zoom in and out as necessary
+TrailBlazer5280 What's the difference? I explained how they are made (the setup), what is recorded (interference pattern) and how you recover the image (with same laser) from what's been made.
Hello I watch this video wondering about 7 d holograms. Is the technology way past where you said it is or is 7d holograms actually just a complex peppers ghost effect?
Yes and no e.g. you can't do CGI in a play. You could imagine being immersed in the set rather than watch things play out on a stage... but this would all be far far in the future, we need to crack the basics first :)
I don't get it. Essentially in his set up he shined a laser onto an apple and then captured the image. Then he also shined some of the original (or identical light) on the that image and somehow that makes it holographic? Why then can't I shine light on a picture and have it turn 3D? I don't understand the difference between what he did and me shining light on a picture.
The hologram doesn't capture an image of the apple, it captures the interference pattern between the light scattering off the apple and the reference beam. Only by shining that reference beam back at the captured interference pattern can you create a 3D image. In the case of a normal picture, there is no interference pattern captured so you can't turn it 3D.
When you take a picture, you capture the light that bounces off an object. The result is a 2D image that looks like the object, from the perspective at which you took the picture. When you make a hologram, you capture the interference pattern that is created when the light that bounces off an object and the light from the original light source are combined. When you record this (on a piece of film or using a digital sensor) the result is a "picture" that looks just like random noise (think the black/white static/noise pattern on an old TV set, if the object is black/white). Then, in order to see the original object, you shine the light from the original light source through this "picture" (that looks like random noise) and on the other side of this picture will appear a three dimensional light pattern that represents the original object. So with holograms you need both a special setup to record it, *and* for people to actually view it later.
ok let me give you the real answer from a specialist...when 2 laser beam hits the plate , where they cross is the interference pattern...the 2 cross patterns engraves and create 2 tiny mirrors that reflects back one pixel and the pixel location in space. if you look at a dot or line just suspending in space straight onward, you cannot tell how far it is...but if you shift your movements you can measure how far or close the dot is using triangulation measurement. hologram uses 2 beams to cut tiny little mirror in the plate that reflections to recreate a scene. laser is used because laser beam travel in straight line and reflect off an object in a straight line. lasers is the only known light that interact with each other when 2 or more beams cross each other on a surface producing a ring wave pattern inaction...where 2 ring wave cross each other the location and intensity of light is presented and burn into the film as tiny little mirrors that reflects back the light pixel location.
Wayne Evans While you roughly capture some of the general concepts, I'd be carefull about calling that a specialist answer. - Not mirrors, but prisms would be a much better description of the hologram. - Where the two beams meet (which is everywhere on the film), they produce a very complex interference pattern that varies throughout the thickness of the emulsion and all across area of the film. - All light travels in straight lines, not just laser light. - Laser are used becaue they produce (nearly) a single wavelength (have a very narrow bandwidth) to give sharp interference patterns and, as a resilt, sharper images. You can view a hologram with an LED of similar wavelength; it will just be blurred due to the range of bandwidths containtd in the LED light. - All light produces interference patterns, not just laser light. A simple lens sitting on a glass plate in white (many wavelengths) light produces interference rings. - Everywhere on the film both the intensity and distance of the object are represented in the interference patterns. ---- And, by the way, *every part* of the hologram film has a *complete image* stored of the *complete object* (as viewed from that spot the film). -- When viewed (reconstructed) all the zillions of minute prisms refract the referencde beam to produte light leaving the film in just the same way the original object reflected the light. Cheers, ScienceAdvisorSteve
I myself has been thinking of re-inventing the original hologram into today's society...there has to be another way...i have a history of finding alternative solutions without loosing original effect...i will find it
hmm, not really because holograms are pretty much pictures. I'd think a play would have to be live. Even a play recorded would be a movie, know what i mean?
+Holobrine Normal photos only capture the intensity of the light. The other key quantity is the phase which depends on the distance the light has travelled. By capturing the interference pattern you can recreate both intensity AND phase, hence you can recreate the exact same light i.e. 3D
a true aerial hologram does not utilize 2d plane for final image generation. If i can't phase my hand through it, it is not a true hologram. That nobel prize was not deserved. Burton inc's aerial hologram on the other hand does. To me, the traditional means of holography is just a wasteful means to create illusions of grandeur.
As Jesus Christ Lord Savoir God says knowledge will increase children getting smarter Way early then ever before all things Auto matic mankind learns to fly like the birds mankind will not be able to hide
