Lately, I've started hearing from its customers, which repaired equipment, that the long-awaited buying an expensive 3D TV brought a disappointment. In the store or on billboards, it was so cool and beautiful, and the house... where are the promised 3D effects?, why does not the conversion of 2D to 3D?, why your eyes get tired, and head to the end of the film, begins to ache unpleasantly?
Anyone has encountered this, here You'll find the answers to all these questions, well, who doesn't want to "pass" in the ophthalmologist's office and to pay for non-existent or implausible effects - read and decide for yourself, again, commendable articles about the "3D" in the Internet - a wagon For those who decided to stay and read, I recommend to start with the following material:
Well, I hope only those who are really interested, so let's start If the vision is all right, we can see all the items that look sharp, assuming that our view is focused on this subject. Closer the object, the more our eyes converge to the center (the nose), such a property as accommodation.
However, there is a chapel: objects placed at a distance, less than 10 cm, we can no longer see the sharp and it's not only in the impossibility of further convergence of the eyes, but the lens can not provide focusing at a predetermined distance. What's the subject matter larger, the greater the minimum distance required to see it whole, without strain to the eyes
If is, the pupil (the optical axis of the view) almost parallel, than objects further away, the more of them gets "the focus" of the eye. How far was the object of our sight, eyes never shifting to the side, such breeding is not natural and nothing good besides tension, fatigue and strabismus, does not portend
We can't see sharp at the same time what is close and what is far, one of the subjects is bound to be blurry or doubled, but!!! costs us to rebuild the view and the sharpness is immediately restored. The closer all these things that look, the greater the distance we can "see" the whole picture (sharpness), otherwise, the eyes produce a "sequential scan" of each of the objects, that is, we do focus our view on each subject to "the full picture".
The restructuring of the focus going smoothly, constantly and continuously,, this process controls the brain, therefore, the idea that I want to address the subject of "In" and that from the subjectAnd" for "In", occur simultaneously, we do not even notice how and what we see our whole world - volume. we choose what to look for in each moment of time and on what subject to focus
Look at anything in front of you - everything has its own volume, the entire secret that is visible to us the volume real, our opinion is all our vision distance and angle from the eye to the subjects on which I look, how strange it may seem, coincides distance and angle from the eye to the subjects. Absurd?, - no, reality, is the reality that it is extremely difficult to artificially put in the "frame" flat screen 3D TV or projector, you now know why
After we learned all the nuances of our vision, let's see how the film and transmission in 3D-format. First of all, you need a special camera, actually consisting of two synchronized cameras or that modern digital camera with two lenses:
Each camera shoots the object under the "my corner", then the image overlap each other and, provided that each eye sees only the image intended for it, retrieves the stereo image or, as is now fashionable to say, 3D image
It is interesting that even in the normal "flat" photography can reach the effect of volume, if you look at the image at the same angle and the same distance from where the survey was carried out. Rate, a couple of "flat" frames and they, in motion, the main secret - in the correct focus on the subject located in the foreground
In order to get on a flat screen three-dimensional image to be "is" not only screen, but for and before, it is necessary to simulate the convergence of the human eyes with cameras. If you place the objects is behind the screen (positive parallax), it will create the effect of "Windows", ie viewer as if looking through a frame placed behind it on the stage. Or you can place the object before (negative parallax), the viewer the impression that the action takes place in his room. Zero (neutral), parallax (sometimes called the vanishing point) is often used for the object of interest in the frame
There are two methods stereo-shooting: parallel axis (the optical axis of the cameras are parallel to each other) and cross axis or convergence (axis, "converge" or "diverge", depending on the pointing to the object, like our eyes). The distance between the cameras (or lenses) is called the sound field or Bassem, let me remind you that to our eyes is about 65 mm, but at what distance to place the camera - depends on the intent of the Director
When viewing 3D images, obtained by the method of recording on the parallel axis, virtual images of distant objects are combined with each other (are in focus), the eyes of the beholder is directed into the distance, and the axis of its eyes, the same parallel as the axis of the shooting lens. The imaginary images of close objects shifted to the right on the left angle and left right angle. Nothing is left eye to turn right and at the same time right eye to turn to your left to "focus" on that object.
When taking on cross axis, images of the foreground objects (close) you can get in front of the screen (negative parallax, the average plan on the screen (zero parallax), and the background behind the screen (positive parallax), depending on the information and the ideas of the Director. Problems can arise with images of remote objects. On the left the perspective shifts to the left, and on the right the right. Until the axis of the eye are parallel, all is well. But if the offsets of the images of distant objects are too large, then the viewer need to open up your eyes to the side to avoid the ghosting that is unnatural
Each method has its advantages and disadvantages. Technique cross axis - it is easier, additional editing and mixing is not required as the focus on the object (foreground or background) is produced immediately by the operator, the main problem is the object on which to focus, selects the Director, not the viewer. As we would not want to consider something else (in the background) - it will not work, it will be blurry, as the translation speed and direction of focus of the eye" imposed on us
Shooting parallel cameras safer for the eye, but without a frame-by-frame manual information, all objects are close relative to the screen, which is unnatural. Mixing is done on the timeline, where a specialist artificially "move" the point of zero parallax (data) on each pair of frames, depending on the intentions of the Director and requirements of optical 3D effects. As a result, once again, we see in focus only what we "should" and not what you want
I think that films in 3D have seen everything. When wearing 3D glasses (in the cinema), the plane of the screen suddenly fails somewhere in the distance, and the foreground objects (people, objects) seem so close that you can reach out a hand. A stunning amount!!!, he, even more than in real life, in which we all see in "3D" that's just ...is it good?
In order for the effect of volume was the maximum, the base distance between the cameras increases, then the difference in images for the left eye and the right eye is the maximum. Also, don't forget that all the near objects we can see from the screen not in their natural size and enlarged. The actors ' faces in the dialogues tend to occupy almost the entire area of the screen if something POPs out rolls or flies close-up - it also takes up most of the screen.
Since the foreground optically located "in front of the screen, the size of the objects visually even increase, and their unnatural volume and close distance cause the eye not only "converges", but "seen from orbit". With the approach of dropping objects sharp eyes were unable to focus on the huge close-up subject, though, according to the Director, the focus should be exactly on it (rest is blurry), if the focus, at this point in time, "conceived" in the middle ground, the foreground is blurred and the natural desire to "see sharp" (aka nose) it becomes impossible
Of course, it was possible to do foreground objects so huge, and instead of excessive approximation to use the removal (in the theater was the play?, - this is the real on-stage volume), however, watch this film is not for huge the screen, occupying all, the visual space, is simply cannot. To create a "presence effect" (regardless of whether you watch in 2D or in 3D) you want the image to occupy all our visual space, as it happens in real life, otherwise get the effect of "Dollhouse"
Let's look at some examples, unfortunately, they're all flat, so will need a little "pofantaziruete" to the extent, however, the beauty is that our brain is capable of it, unless the person is suffering a complete lack of imagination and fantasies.
Click on the "button" and look at the picture, mentally as close her, what do we see? Before us a large room (20x10 metres, no less), the eyes then "calculate" its size, and the brain consolidates all the information about every item in the room, to create a "correct three-dimensional image":
but, it is necessary to restrict this hall is the size of the "screen" before us "Dollhouse" and all the effects of something big instantly disappear, we see no interior, and their small models, the brain stubbornly puts it all in 50х20 cm and flatly refuses to believe in the "bigness" of the hall
The second example (mentally only see the picture and imagine that she, at least, on the entire screen of the monitor ) - a city from height of bird's flight, the view extends for tens of kilometers:
but not to tens of meters, visible borders of the layout, destroy the effect of the presence (of a flight over a large city) fully
The next problem is crossing the boundaries of the screen, if this object is the foreground, shot with negative parallax (i.e., visually located in front of the screen). In this case, our eyes and brain receive two completely opposite information: one that the object is in front of the screen (so it was intended when shooting), and second that he is behind the screen, as we clearly see the edge of the screen. This inconsistency mask for surveying and installation (semi-transparent layers and masks), but it works only on a huge cinema screens
In the is any 3D TV or 3D monitor, we see that the main "characters" of the image (fish, birds, water, dragons...) always are partially chapels. What's so surprising?, we like it and really want to see it "live" at home, buying such a "wonderful" TV:
Buy, look.... well? and when che comes out of TV as advertising??? And never, it's not like this is a publicity stunt, used for it seemed to us that 3D TV is capable of. As we remember, to create any 3D effect, you need to have two images and two eyes (the material is presented by first link, just above).
Both images, regardless of their "three-dimensionality", are displayed on the flat panel display of a TV or a projector, again, flat screen theater with limited size. All images (for each eye) are projected or reflected only in the aisles of this screen, behind the screen no part of the image to be displayed cannot, simply because there no.
Yes, we do seem, when viewed with 3D glasses that the eagle right in front of us, even the hand can reach, but it will only in the aisles, if we sit closer to the TV, and right, if viewed at an angle (as sketched in advertising), the 3D effects is not at all (more about 3D glasses I wrote in second part of the article about 3D)
"I bought a new 3D TV, and why it's not working?" - I heard this often, only it turns out that everything works, except the "volume" for which it actually took. Broadcast in 3D-format yet, the DVD support it, and the discs themselves are quite expensive, and promised to convert normal images in the volume are only good in words
Modern 3D TVs, according to the advertisement, is able to convert (translate) a simple flat image in 3D. Theoretically it's possible, however with minor huge detail, but let us order try to make 2D - 3D "on the fly", i.e. in the mode of live view as impossible how to Dolby 5.1 from one monochannel. The volume will come from "nowhere", where he never was, unless you do it artificially in time-lapse. Remember the movie "Alice in Wonderland"?,- anyone watched it in 3D cinema, I noticed that "volume"-that is, only some characters are flat, as in children's "books-cots"
The secret is that this film, like "Titanic", one shot with a regular camera, and all the 3D effects were created manually, on the timeline. The characters and scenery created from scratch using the computer, it is easy to give a "natural volume" because they are already created as three-dimensional models, but actors and real scenery with attributes - they become flat because of the lack of information on the frame of their volume. Try their "turn" to create the separate frames of a stereo film, it is to turn the figure of a man cut from paper
It turns out, as on the stereo-the calendars, the layers (front, middle, background), creating volume, there are, but by themselves - they are "flat". Please note, background (background) on them is blurred, it creates additional volume effect even now, when viewing images on a conventional monitor, while trying to focus on distant details - nothing happens. This technique is often used by photographers to highlight the foreground objects, but for a long film - I'm not sure my eyes will love it
Where 3D TV, when converting the simple image, can be obtained at: the object must be placed before or for screen? If the first object (the car) overrides the second (house), means the first - is closer and I can put forward logical?, - like Yes, only for this TV, you need to scan the each on each frame and select it for ourselves, the way we allocated a "magic wand" areas of the picture in the "photoshop"
For this you need a perfect signal (about the "ripples" of speech in General can not be), all the plots of the images must have clear color boundary, which is impossible in a real film (with cartoons - it is easier)... and do not change over time (movement), otherwise, where TV finds out, it's still the object or the part of another.
Can you imagine what must be the "power" of such a 3D-processor, and how much it should cost, to do all of this continuously and correctly in each frame, in real time? at least, the 3D TV must be water-cooled and the inside stuffing of several of the most sophisticated "gaming" computers what do You think, is it? Of course not, so do not expect a "conversion" too much
Besides all this, there awaits us another portion of the "glitches" associated with the inevitable conversion errors. Imagine that near the house, on the road, a parked car, a man walks down the sidewalk past the house, ie it moves relative to home, 3D "puts" it to the foreground (in front of the screen), he goes behind a car and immediately becomes "background" and the machine "climbs" forward; gets in the car - car again goes back and starts to go again "foreground" If You are wondering what are the effects of three-dimensional image on a flat screen, go here: Optical illusions, the world volume
What conclusions can be drawn from all the above, first of all, there is less need to believe the advertising tricks, remember, it is better once to see than hundred times to read about it. Is it possible to watch movies in 3D-format?, - it is possible, but not always and, best of all, on the big screen of the cinema, where the screen takes up our entire visual space, so all the effects will be maximized, just do not sit too close to the screen, it's better out, then to eye with each other did not say Hello