Stereography, or 3D photography — this is an image that allows you to see the captured object in three-dimensional. Such an effect, from the moment the image is created to its reproduction, is achieved by various methods. However, all of them are based on only one principle — the peculiarity of binocular vision inherent in people.
A person has two eyes, each of which fixes its own image. In the brain, they are superimposed one on top of the other, and we perceive a three-dimensional picture of reality. Given that the distance between the pupils is 6–6.5 centimeters, the eyes see distant objects with only a slight distortion.
It is the same with stereo photography: objects are photographed from two or more different points spaced from each other on a stereo basis. You can do this with single or dual camerasspecial stereo camera or stereo nozzles. The resulting images are called a stereopair.
stereobasis — the distance between the two points from which the survey is made. The optimal stereo basis for creating a three-dimensional image at a distance of less than 100 meters is 65 millimeters (as between the pupils), further — 1/500 of the distance to the subject.
The fact that the volume of the picture is due to the fact that each eye sees slightly different pictures of the same object was known by Euclid. Following him, this feature was described by Leonardo da Vinci in 1584. The theory of stereoscopic perception was described in detail in his work Dioptrics in 1611 by the German optician and mathematician Johannes Kepler (Johannes Kepler).
In 1600, the Italian painter Giovanni Battista della Porta (Giovanni Battista della Porta) wrote the first stereo image. A hundred years later, his compatriot Jacopo Gimenti da Empole repeated his experience (Jacopo Chimenti da Empoli), then, in the middle of the next century, the French Bois-Claire (G. A. Bois-Clair) and, in the 1900s, the Spaniard Salvador Dali.
Stereo photography was invented by King’s College London professor Charles Wheatstone (Charles Wheatstone). In 1833, he created a mirror stereoscope — a device that allows you to see a three-dimensional picture using a pre-filmed stereo pair.
The first camera with two lenses was designed by Scotsman David Brewster in 1849.David Brewster); he also built a stereoscope without mirrors. Six years later, the scientist also developed the first stereo reflex attachment for a camera with a single lens.
In the middle of the 19th century, stereo photography was especially popular in Great Britain. So, one of the first amateur photographers of this genre was the British aristocrat Clementine Hawarden (Clementine Hawarden). Her favorite subject is Dundrum Manor in Ireland. Today, a large number of stereo pairs taken by Hawarden in 1857–1864 are kept in the collection of the Victoria and Albert Museum in London.
In 1858 the Frenchman Joseph d’Almeida (Joseph d’Almeida) discovered an anaglyph method for representing stereo pairs. It has long been used to create books, comics, maps and postcards. In the 1920s, plastigrams appeared — the first anaglyph films.
With one camera
The simplest method. The camera is moved horizontally, sometimes along special guides, to the distance of the stereo basis. The disadvantage of this method of shooting is that it is impossible to fix moving objects.
With a stereo camera
The most optimal method of 3D-shooting. Stereo cameras are, in fact, two cameras combined in one body: they have a common viewfinder and tape path, but different shutters. Some of these devices may have more than two lenses — in this case, it becomes possible to “look” behind the main subject.
On the ebay you can find functioning 3D retro film cameras in good quality for 7–15 thousand rubles. Today, a Japanese company is engaged in the production of amateur digital stereoscopic cameras. fujifilm.
With two cameras
Cameras are usually mounted on a horizontal rail. From the pros: now you can capture both having fun and birds flying in the sky. However, this method requires precise shutter timing, which can be achieved using a radio trigger.
With a stereo attachment
The stereo attachment is mounted directly on the lens of a conventional camera. The prisms and mirrors in the accessory frame the visible field of the camera into two, as if from different angles.
Modern 3D lenses are more compact and functional compared to the “oldies”. If you are going to buy a stereo attachment for a film camera, then I advise you to still look at something from a rarity, and if for a digital one — a company Panasonic and fujifilm offer several models.
STEREO PAIR VARIETY
Regardless of how the stereo pairs were obtained, they can be observed in various ways. For example, with the naked eye, with a stereoscope, a dual overhead projector, and on a flat print (lenticular print or two-color anaglyph image). There are several options for representing stereopairs.
In a stereoscope, one eyepiece shows one of the images of the stereo pair, the other shows the other. With lenticular printing, each of the pictures is applied to the grooves of a certain parity. For anaglyph images, glasses with red and green filters are used (these used to be issued when watching 3D movies).
Horizontal stereo pair (side by side). Parallel
The right image is for the right eye, the left image is for the left. You need to look at such a couple directly.
Horizontal stereo pair (side by side). cross
It differs from parallel in that the left image was taken as if we were looking at the object with the right eye, and vice versa. To consider such a pair, you need to cross your eyes.
Interlaced stereo pair (Interlaced)
By breaking the image into vertical stripes one pixel wide, we get a vertical scan. Now in each even line we write a picture of one angle, and in the rest — another. Congratulations, we got an interlaced stereo pair.
One of the images of the stereopair is passed through one filter (for example, red), and the other through the second (for example, green). In order for objects to become voluminous, you need to wear stereo glasses with glasses of the appropriate colors.
Page flip (Page-flip)
With this way of representing a stereopair, it is not static. So, even frames display the image of one angle, odd — another. The page flip effect can be achieved both with the help of an edited video (for example, gif-format, as in the examples below), and special glasses that close and open the shutters alternately for the right and left eyes in time with the frames.
Regular and stereo photography appeared almost simultaneously. However, at the beginning of the 20th century, photographers perceived 3D images as mass entertainment, not art. So, at one time, attractions based on the stereoscopic effect, and boxes with stereographic images, which depicted views of distant countries, rural landscapes or nude models, were popular.
In the 1950s and 60s, there was a surge of mass interest in 3D photography: companies were looking for new technological solutions and developing more models of special cameras, attachments and devices for viewing stereo pairs. Today, the technical base of 3D photography continues to improve, which means that in the future a three-dimensional image may become a popular genre of artistic photography. Dare!
In my previous materials, I talked about the principles and tools of shooting in infrared and ultraviolet spectra.