What Are 3D Digital Cameras?

Three-Dimensional (3D) digital cameras take a picture with two lenses to create an image that looks three dimensional. Several options are available commercially, and photographers can also create their own systems if commercial ones do not meet their needs. In addition to still photography, 3D video is an option with some products. Working with digital files can be much easier than handling film when it comes to dealing with issues like registration for 3D images, making it accessible to amateur photographers.

In commercial 3D digital cameras, the face of the camera includes two offset lenses. When the photographer presses the shutter, the camera records two images, which can be merged to create a single three-dimensional picture. A toggle may allow people to switch between two and three-dimensional photography for different environments, and it also possible to change between still and video. 3D digital cameras have varying resolutions and quality, depending on model, manufacturer, and intended user populations.

Several types of 3D technology are in use. Some, for example, use colorized layers which must be viewed through special glasses for objects to pop out of the image. Others require people to cross their eyes to see the illusion, or utilize side-by-side pairing and a stereoscopic viewer. 3D digital cameras may enable one or more of these options for the photographer. This can create flexibility to allow photographers to decide on the best choice for a given application.


Photographers may also create their own 3D digital cameras. They pair two cameras side by side, typically using the same model for consistency, in a mount that holds them stable. One advantage to using a mount is the ability to adjust camera position and distance, which can be used to create more depth in the resulting image. Using automated controls, the photographer can snap two simultaneous pictures on the cameras, and process them together in an image editing program to create a three-dimensional image later.

Buyers considering 3D digital cameras may want to try several models to see how they feel, and can ask to see sample images to get an idea of overall quality. Some control systems are more intuitive than others, and the feeling of the camera body can also have an impact; if a camera isn’t comfortable to hold, it won’t be comfortable to use. It can also be important to consider things like resolution, available 3D technologies, and available warranty.

What Is the Difference Between 3D and 2D?

The terms "three-dimensional" (3D or 3-D) and "two-dimensional" (2D or 2-D) are most commonly used in reference to photography and other graphic image technology, such as animation and computer graphics. The difference between 3D and 2D images is that 3D images add the perception of depth. A 2D image, on the other hand, has only height and width. The term "three-dimensional" also is sometimes used to describe a physical item such as a sculpture or mobile, which could be described as three-dimensional art, in comparison with a two-dimensional painting.

Three-dimensional imagery cannot be created without duplicating the effect of two eyes working in tandem, which allows three-dimensional perceptive effects such as depth perception. Early 3D technology imitated this process with dual-camera or dual-lens setups. Modern computer technology can easily create realistic effects in both 3D and 2D.

Photography records images for reproduction on flat, two-dimensional surfaces, such as paper prints or display screens. This has the effect of flattening the image, reducing or eliminating the effect of depth. Natural vision produces this effect because the eyes are set slightly apart, allowing the brain to process two different views of the same image. During the late 19th century, photographers attempted to rectify this problem with dual still and motion cameras that were designed to work in tandem. Viewing these “stereoscopic” images through special viewers simulated the effect of seeing a three-dimensional image.


The terms 3D and 2D first came into popular use because of the film industry. During the 1950s, Hollywood filmmakers experimented with 3D movies as a marketing gimmick. These movies were filmed with a variation on the stereoscopic dual-camera setups. They were expensive to produce and required viewers to wear special glasses to experience the 3D effect. Only a few of these movies became lasting classics, most in the horror/suspense genre, such as House of Wax, Creature from the Black Lagoon and Alfred Hitchcock’s Dial M for Murder.

A second wave of 3D films in the 1980s had similar results. The earliest video games, meanwhile, also had 2D graphics, but in the 1980s and 1990s, rapid advances in computer processing and memory made more realistic images possible. By the 21st century, computer-generated imagery (CGI) could create 3D and 2D effects for big and small screens alike. In 2009, James Cameron’s film Avatar pioneered a new wave of cinematic 3D by combining cutting-edge CGI and digital filmmaking technology. Soon, many of Hollywood’s big-budget effects films were following suit.

In real life, there is another crucial difference between 3D and 2D vision. Three-dimensional vision contributes to depth perception, or the ability to estimate an object’s distance. This fact has been humorously pointed out on the science fiction television series Futurama because one of the show’s main characters, Leela, has only one eye. Despite being the pilot of an interstellar space ship, Leela often complains that she has no depth perception. Ironically, Andre de Toth, the director of the famous 3D film House of Wax, also had only one eye, and he could not see in 3D.

What Are Passive 3D Televisions?

Passive 3D televisions are three-dimensional TVs that use passive glasses that rely on different light waves rather than relying on battery power. The glasses used with passive 3D televisions are polarized in a specific way to block different forms of light for each eye, creating the illusion of depth. This stands as an alternative to active 3D televisions, but may present a problem for people who have trouble perceiving depth. Both the passive televisions and passive glasses are cheaper than the active forms, and the glasses are substantially lighter than active 3D glasses, which require batteries.

To create the illusion of depth and achieve a 3D image, each eye has to be presented with a different image. Not only does the eye have to see another image, but it has to see both at once through each eye, causing the brain to combine the images and create a depth illusion. With passive 3D glasses, a special polarizing process similar to that done with sunglasses takes care of the problem. The difference is that sunglasses dim all forms of light, while passive 3D glasses dim different colors and forms of light for each eye, causing each eye to perceive the image differently.


Passive 3D televisions are any that use these passive glasses. There is usually an option to change between two-dimensional (2D) and 3D viewing, because some people may want to limit their exposure to 3D or would prefer to see a particular movie or show in 2D. Unlike active 3D televisions, which have an infrared device that interacts with the glasses, passive 3D televisions do not include this. The passive glasses also can be used with any passive television, regardless of make or model.

There are some problems with passive 3D televisions, particular to the passive technology itself. Sometimes movies and shows will blur or will not appear entirely 3D, because the glasses are made to work in a general way and can misinterpret light. The 3D effect also can only be viewed from certain angles, so users need to sit directly in front of the television to get the full effect. Concentrating on particular spots on the screen also can cause eye irritation, but this goes for both active and passive 3D glasses.

While there are some trade-offs in image quality with passive 3D televisions, there also are advantages. The biggest one is price, because both the television and the glasses are much cheaper than their active counterparts. Glasses do not use batteries, so chargers are not needed. The glasses also are much lighter, which helps users relax when using the glasses.

What Are the Different Types of 3D Glasses?

All types of 3D glasses can be divided into two categories: passive and active. Active 3D glasses interact wirelessly with images on a screen to enhance 3D viewing, whereas passive glasses do not. Passive 3D glasses have been around since three-dimensional viewing first arrived in the 1920s, and are themselves divided into two major subcategories: anaglyphic and polarized glasses.

Practically anyone who has ever seen a 3D movie is familiar with anaglyph glasses, which feature a combination of red and blue lenses. Anaglyphic 3D works by projecting two identical but slightly offset images on a screen, each image tinted with a different color. To the naked eye, an anaglyphic image appears blurry, with reddish and bluish hues. The glasses use color-filtering lenses to target one image to the right eye, and another to the left; the result is that each eye sees a different image, but the mind is tricked into believing it sees only one. The mind compensates for this by focusing in between the two offset images and blending them into one, which creates an illusion of depth.


Passive polarized glasses operate on the same basis as anaglyph glasses, only they filter light waves rather than color. Again, two identical and slightly offset images are superimposed, except in this case each image is polarized to project light differently than the other. With polarized 3D glasses, each eye only processes one image. Again, however, the mind is tricked into blending the two images into one, creating a 3D experience. Unlike anaglyphic 3D, which can be projected from any screen, polarization 3D works best with screens able to relay different light frequencies without sacrificing picture quality.

On a simpler scale, Pulfrich glasses can also create a 3D effect, but only with objects moving across the viewer's plane of vision. These 3D glasses have one completely transparent lens, and another that is heavily tinted. As an object moves across the visionary plane, the image is immediately transmitted to the eye through the transparent lens, but the tinted lens causes a slight delay. This delay causes the brain to add more depth to the image, creating somewhat of a 3D effect.

Since the advent of LCD technology, which is capable of digitally transmitting images at super high-speeds, 3D glasses have made great technological leaps and bounds. Today, active shutter glasses are able to communicate wirelessly with an LCD display, interacting with the action on the screen via infrared signals. This enables the lens on active glasses to shutter back and forth between different light filters, further enhancing the 3D viewing experience.

Another significant upside to active technology is that it is adaptable to 3D TV sets. A 3D-ready television set, a pair of active shutter glasses, and a stereoscopic sync signal connector will allow the LCD display and glasses to communicate with one another. A growing number of television broadcasts are being produced to take advantage of this technology.

What Is a 3D Projection?

Three dimensional, or 3D, projection, which is often called 3D projection mapping, is the transference of three-dimensional data onto a two-dimensional plane. Scientists, engineers, and designers often make use of this type of mapping system when making computer or pen and paper models of three-dimensional objects. Objects may be drawn to scale or with perspective, but both qualities cannot be kept intact after translating three dimensional coordinates into two dimensions. Though 3D projection usually refers to the modeling itself, it can also refer to the projection of images that appear to be in three dimensions, such as those seen in 3D films.

By its nature, the act of transferring three dimensional information onto a two dimensional plane means that something must be lost. There are two main ways to use 3D projection, and each has its own positive and negative qualities. One way to project a three dimensional image onto a two dimensional surface is by using perspective. Perspective makes an image look to the eye as if it were three dimensional, though the sizes of the parts of that object, if measured, would not be proportionally correct. The other way to use two dimensions to represent three is to use a system called orthographic projection. In this system, the measurements are accurate but the object will not look like it has depth.


There are a number of uses for 3D projection. Engineering design and drafting both make use of three dimensional coordinate systems in the design of buildings and structures. Computer graphics also use 3D projection when modeling a three dimensional object or environment in the two dimensional space of a computer screen. Science and mathematics may also use this type of projection when modeling or graphing various natural phenomena and equations.

3D projection can also refer to the projection of two dimensional images onto a screen in such a way that they appear to the viewer to exist in three dimensions. The technology to make a two dimensional image appear to have depth has been available since the 1920s, and though there have been many improvements, the basic principles are the same. Instead of one image, two images that overlap slightly are placed on a screen at the same time. When a person is wearing special glasses, either color filters or polarized filters, each eye is only able to see one of these images, and the brain translates the information received by each eye into one three dimensional image.

What Is Digital 3D?

Digital 3D uses polarization to make a 2D image appear three-dimensional. Typically used in movies, polarized glasses are required to see the 3D movement, but images can also be viewed without lenses, though they may appear blurry. Digital 3D does not use color variation, which used red, blue, and green to create 3D effects in older movies.

Human eyes are binocular. This means each eye sees a different portion of an image, and the two are combined to create one image in the brain. Traditional 3D images are color coded red and blue. Lenses worn with corresponding colors allow eyes to see images that appear to have depth beyond the screen. Using color variants can cause images to appear off color.

Digital 3D uses many of these concepts, but replaced color variants with polarization. Images are polarized and glasses worn with lenses made of different polarizations create a 3D effect. Movie theaters typically use one or two projectors to display digital 3D movies on screen. If one projector is used, a switch may be installed to control image polarization. When two projectors are used, images are displayed to both eyes simultaneously.

Digital 3D animation started slowly in movies. Chicken Little was first released in North America in 2005. Digital animation was used to create the film, which was later rendered for 3D viewing. Later, previously released movies, like The Nightmare Before Christmas, Toy Story, and Toy Story 2, were re-released as 3D movies.


Today, watching 3D movies on home television sets requires the use of 3D glasses. The electronics company Philips was the first to develop a home television that can display digital 3D images without glasses. With it, a lens is placed on the surface of the television to create a digital 3D effect. Traditional television stations or movies tend to appear blurry on this set, however, and consumers report that images can be distorted from certain angles.

Digital 3D images are also found on the Internet. These images do not use the same 3D technology as movies and television. Usually, these use shadows and movement to trick viewers into seeing what appears to be a 3D image on screen. Digital art and computer wallpapers are also commonly found in digital 3D.

One of the more popular 3D art pieces is the autostereogram. The images represent a 3D picture placed within a 2D work of art. When eyes are forced out of focus, a second image can typically be seen. Some viewers report feeling a pulling of eye muscles as they concentrate on one of these hidden pictures.

What Are 3D Sunglasses?

Three dimensional (3D) sunglasses are an entertainment accessory that take advantage of our binocular vision and are able to make a specially prepared two dimensional image appear to be three dimensional. Binocular vision is the term used to describe the image resulting from two eyes being used simultaneously, as humans do. When an image or film has been prepared for use with 3D sunglasses, it is actually comprised of two images, one intended for each eye. The 3D sunglasses force each eye to see only one of the images, and the brain then combines the two, which creates the illusion of a three dimensional image "popping out" from the surface the image or film is being viewed on.

Binocular vision results in a single image being perceived as a result of binocular fusion, which is the process in which the brain takes the two slightly different perceptions of each eye and combines them. This is an useful ability that produces a wide field of view, increased depth perception, and the ability to see faint or far-away objects more easily than if the viewer had only one eye. This is the primary driving force behind the function of 3D sunglasses, which filter distinct images into each eye. Binocular fusion causes the brain to unite these images so that, while there are two images, the viewer perceives only a single picture.


There are several different ways in which 3D sunglasses accomplish the isolation of each image for each eye, but the most commonly used are dual-color lenses and polarized lenses. The lenses in dual-color 3D sunglasses are usually red and blue or red and green. The image that has been prepared for viewing shares these colors. Polarized lenses make use of light polarization, which is the process in which light waves are made to move in only one direction. Each polarized lens detects one source of light.

Images or films intended to be viewed with 3D sunglasses will have two different images that have been spaced slightly apart, either in colors that correspond to those on dual-color 3D glasses or as light patterns intended to be viewed by polarized 3D sunglasses. Polarized images are generally considered superior to dual-color images as they allow for full color to be viewed. Since dual-color 3D sunglasses use color to separate the images, the quality and richness of the color is significantly reduced.

What Are 3D Video Cameras?

Three-dimensional (3D) video cameras are recording devices able to produce 3D movies rather than flat two-dimensional (2D) movies that lack depth. Most 3D video cameras are made for the consumer market, so they often are fairly small and inexpensive. Traditionally, 3D movies were made using two side-by-side cameras, but 3D video cameras replicate this effect by using two side-by-side lenses. To increase the quality from consumer-level to broadcast-level, the camera and lenses must be larger. Depending on the cameras, the 3D effect may require glasses for the viewer to see the depth.

When the 3D effect was first made for movies, it was done by strapping two cameras together so they could make images for the left and right eyes. While this method is a little clunky and there is a high chance of recording inaccuracy, it mostly is replicated in 3D video cameras. Instead of using two different cameras, these cameras use two different lenses to make separate images for the left and right eyes, or mirrors are used to create this effect. There often is internal software that automatically combines the two movies into one to generate the 3D movie.

Most 3D video cameras are made for the consumer market. These cameras are not supposed to create broadcast-quality movies, so they typically are fairly small and inexpensive. This makes 3D movie technology more accessible to people who are making amateur and home movies while still delivering a quality 3D experience.


Broadcast-quality 3D video cameras use technology similar to the consumer-grade version, but they are larger and the 3D effect can be projected on larger screens. Aside from these cameras being bigger, the largest difference is found in the lenses. The cameras’ build usually is too large to enable two lenses to properly fit into these cameras, so a mirror is used to mimic the effect. The 3D lenses are bigger, so the footage will have better quality and the 3D effect should appear more realistic.

People may need special glasses to accurately view movies made with 3D video cameras, depending on the camera and what the user wants. Some people may find wearing the glasses to be annoying and, while the non-glasses version is usually not as accurate, it is a viable option. Using glasses often increases the 3D effect and tends to produce the most accurate 3D video; the 3D effect also can be viewed from all angles, while the non-glasses version has to be watched head-on.