How Does Rear Projection Work? – [Process & Complete Guide]

You can use overhead stereopticon as the backstage magic lantern, but how does rear projection work? You might be thinking we have to add an extension or replace some equipment.

Hind magic lanterns have been very crucial parts of the media industry in the 1900s and are still used due to their fantastic noise management and the freedom they give to the presenter.

Here We are going to discuss their working and tricks of operating them for obtaining extraordinary view. Let us start!


What Is The Operating Principle of The Backstage Stereopticon?

This technique was used in films and dramas in the 19070s to create a background according to their scenes that are not reachable in real. Thus, in movies of the 1970s, in every location where two-person are talking and moving in the car ahead, it is for sure that their background is virtual.

What Is The Operating Principle Of The Backstage Stereopticon?

However, these were helpful in the past, but their visuals were not very accurate, and people of this generation can quickly pick out that the background is not real.

Nowadays, modern techniques are used to create a virtual background; however, whenever directors and producers want to present something from old age or something obscure, they use rear projection instead of the front.

Parts of Backstage Magic Lantern

To understand how does rear projection works, which was the main equipment for shooting movies from the 1930s to 1970s, let’s first jump into its parts, their placement, and each piece’s function individually.

Its most basic parts are.

  1. Projector
  2. Screen
  3. Foreground Subject
  4. Camera

Subjects are positioned in between screen and camera, and on the other side of the camera, there is a projector which is representing pre-recorded videos or still images.

During the screen shooting to which you provide the rear projection background, if there is still an image, it is known as a process shot. But if a video is playing, then it will be known as a transparency shot.


The process of backstage positioned stereopticon is not very demanding. Once you have set your projector correctly, the projector behind the screen will present your desired visual on it, so your audience is at the front side can enjoy the whole scenario.

Ensure all the electrical connections are secured, and there is no absence of current between the presentation.

Benefits of Rear Projection

Undeniably front stereopticon is finer and sharper in their work, but the result of the backside placed stereopticon can not be overthrown when it comes to the commercial level.

After learning how does rear projection work, it will be easy for you to understand why they work better than the front projection in some situations.

Successfully Shot Movies

The major benefit of hind magic lanterns is in the media industry, as many successful movies have been made using virtual backgrounds. In return, they got the love of people very much, and industry earned a lot.

Guardian of the galaxy vol. 2, wonder woman 1984 both these earned a lot of fame were shooted by using virtual reality with the help of a rear overhead magic lantern.

Adaptable Lightnin

When you present something in the front stereopticon, it is mandatory to censor the light and keep a check on it. But after scanning how does rear projection work, you can guess the lighting required for the rear projection.

In this kind of magic lantern, you have many margins as you do not need to focus very much on the lighting as you can go with simple lighting without being creating a pain point for viewers.

Helps in Cuckolding the Audience

Whenever you present something, whether on-screen in theatre, it is your responsibility to present the environment according to your script, there must not be any hindrance, and none of them should let to know how does rear projection work and where it is placed.

Rear projections are very helpful in this scenario. They are easy to hide; no one can pick them out, thus creating a fully immersive environment for the audience, but the front projections are easily noticeable.

Types of Rear Projectors

Switchable Rear Projection

These stereopticons instantly switch themselves from a screen full of covers to completely transparent sheets. People most commonly use these for advertisement.

As you may have seen in many hotels and in retail centers where a screen is shown full of visuals, suddenly there is nothing you can see inside through the glass. This all is due to the switchable rear stereopticons.

Optical Large-Format Projections Screen

These are very massive in size and are placed in open areas to attract people’s mass and amuse them like most banks, museums, and shopping centers. These are mostly placed in the center to increase beauty.

In such stereopticons, the screen is made of glass or acrylic, on which there is a coating of unique optical diffusions material. This whole combination results in the viewing angle from 60 to 120 degrees and justification of how does rear projection work.

Rear Projection Holographic Screen

If you want to create a Halloween type of scene and show a horror movie or drama, these holographic magic lanterns are used. Their templates were widely used in the 83rd academy awards, MV EMAS’s.

They have a wide range as you can use self-adhesive film, acrylic screen, glass which is affordable to you. On this, all the imaginary things feel real as their viewing angle is 140 degrees, 82 % transmittance, and aspect ratios are following 16:9, 16:10,4:3.

Pros of Rear Projection

  • Back stereopticons are placed at the backside of the screen, giving a major flex over from projectors as they are placed in the front of the screen, so you have to provide customized space to them; thus, there is disturbance both for the audience and projects.

But in the case of back projectors, you can easily set them backstage and do not even have to focus on them.

  • It is famous in people that the visuals of front stereopticon are best and most clean, but it is not true when you place back-stereopticon at the right place and when ample light is provided to it then hind stereopticons work much better than front magic lanterns.
  • People who want to organize an event within a limited budget and have to use visuals prefer back stereopticon as they demand less lighting; thus, by arranging a few bulbs, you can successfully preset your point of view on the screen with a 100% clear vision rate.
  • One major element of back-placed stereopticons is that they do not produce noise. The noise level is almost zero, which further helps convey the message regardless of bright front stereopticons whose noise level is highly distracting.


  • It is mandatory to keep the projector near the screen, but it has one downfall you can not use a standard lens; instead, a short-throw lens is required to fill the screen
  • In this setup, a lot of light has reflected the projectors; as a result, the overall brightening of the screen decreases, affecting the quality for audiences
  • You separately have to invest in a special screen that allows the maximum light to pass through as other general screens cannot pass the full light to screen for the audience. The expense of a screen is maybe very much for some people.

Frequently Asked Question’s

Do I Need a Particular Projector For The Rear Projection?

It may seem that the backstage stereopticon is different, but the fact that any magic lantern can be revered to use as a behind-screen placed magic lantern. But if your backstage has less space, then to throw a complete picture short through a lens projector is required.

How Much Space is Required For Rear Projection?

The space required for using the rear projection depends on the lens and stereopticon you are using. For example, if you are using short-thrown stereopticons with a ratio of 0.8:1, then the distance must equal the screen width.

But if you are using a standard projector with zoom lenses in the ratio of 1.5-2:1, then space must be equal to almost 2  times the screen width.

Is There Any Shadow in The Rear Projection?

If you pass from the magic lantern’s front, your shadow falls on the screen, and the screen distorts. But backstage positioned stereopticons are breathtaking because there is no issue of shadow; thus, it gives more freedom to the presenter he can move here and there freely.

Final Words

In a nutshell, the working of the rear stereopticon is the contrast of front protection but easy. We have to keep the projector behind the screen with ample lighting to present visuals to the audience.

A small overthrow stereopticon lens is used in limited space, which does not make noise, hence helping us present our point. It has many types, but all have the same working principle.

For further inquiries and doubts, comment in the below comment section. Thank you for visiting us!

Hi, this is Boris! I was interested in writing about the tech gears. After getting an enormous amount of information about tech gadgets, I thought to share it with others too. So I started writing about all the stuff that is helpful and innovative.

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