How Do 3D Projectors Work? [Simple Answer]

There has been a vast improvement in the 3D projection world over the last couple of years. It has been a changing experience for all of us at the movie theaters and home as well.

A lot of people think that 3D was introduced to the world by the time that Avatar movie was out in 2009. However, this is not true. 3D projectors have been around for a long time.

It all started in the early 90s. Yet, it wasn’t popular because the resolution was too low, and scientists had to work on developing it. Then by the year 2010, the first 1080p 3D projector was out, and everything changed. However, if you are interested in 3D projectors you may take the BenQ HT2150ST which is one of the best 3D short throw projectors.

Nowadays, there is a variety of projectors available on the market, and the best part is, it only keeps getting better.

The Basics of Understanding 3D imaging “Stereoscopic Vision” or “Stereopsis.”

Basics of Understanding 3D imaging

It is the ability of your brain to get a sense of depth and 3-dimensional structure from the surrounding visual inputs. Your visual cortex combines different images seen by both your eyes simultaneously to produce a single, deep, and a three-dimensional image.

This means that for you to see in 3D, there must be a slight difference between the images delivered for your eyes.

And to make this happen, scientists came up with the idea of making special glasses that made your eyes receive a different perspective of the image displays. 

The rest of the process happens in your brain, and it creates the illusion of depth.

This is how Anaglyph images were produced.

Anaglyph 3D Imaging

It was the first and most basic 3D production technique. It depended on wearing glasses that made one eye receive a red-tinted image, and the other gets a blue-tinted. This was done by using special filters to make the lenses of these glasses.

The early anaglyph imaging wasn’t satisfactory, and it faced a lot of issues. First of all, the details weren’t precise in 3D scenes because the color separation was very minimal.

Another issue that faced scientists  was what the scientist called “ghosting.” Because of the limited separation, images that are meant to be perceived by the right eye could creep to the left eye and vice versa.

The last issue was that the screens at the movie theaters needed to install silver screens because they were more reflective and helped make the separation more stable.

This made the entire technology weak and in need of improvement.

Polarizing System 3D Images

It is the most commonly used 3D system at movie theaters nowadays. The general idea that the system depends on is adding special polarizing filters on the screens that force the light to move in two different directions, each intended to reach one eye.

The glasses you wear on your eyes should be made with special filters, as well. One significant disadvantage of this system is that it compromises the brightness of the display since the light projecting out is divided between both eyes.

 However, later on, cinemas started using two projectors to make up for this drawback.

With the improvement of the polarizing system, the circular polarizing system came up next. It is now used more widely. What happens is that the filters change the linear light beam into a circular one.

To make this happen, one component of the electric field should be slowed down. So, if you have a vertical element and a horizontal one, it would seem as if the light is rotating, creating depth in the image projected. This way, there’s no need to use two projectors.

Dolby 3D Systems 

You might have heard this name before as it became popular in all the movie theaters. Dolby laboratories developed it, and it can show both 2D and 3D films. It depends on using an additional color wheel containing a filter for red, blue, and green colors.

This filter is added to the initially placed wheel to produce a 2D film. However, the additional wheel produces the colors at different wavelengths than the original wheel. This way, the same screen can be used to display 2D and 3D films. This technology is called “wavelength multiplex visualization.”

The best part about this technology is that it works on conventional screens. It produces a brighter and sharper image than that used by circular polarization. This makes it more convenient to use in all movie theaters.

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