Holograms have been around for decades, but compared to other forms of thriving technologies their development has been relatively slow.  Historically, holograms have been limited by the cost of materials and the lack of technology to create and store them, as well as the limitations of the human eye. 

As a result, early holograms lacked detail, had limited viewing angles, and could only be seen under certain conditions. 

Additionally, many of the early holograms were monochromatic and the materials used to create them were fragile, meaning they could degrade over time.

Times have changed. In recent years, advancements in technology have made it possible to create much more complex and detailed holograms. This has allowed for the development of 3D holograms, which can be seen from multiple angles and have a greater level of realism than before. 

Another thing that is growing side to side with holograms is fake holograms. These fake holograms are becoming increasingly more realistic, allowing for even more creative applications. From entertainment to marketing, fake holograms are opening up a world of possibilities for businesses and consumers alike.

What is a Real Hologram?

A hologram or holography is a photographic technique that records the light scattered from the subject and then presents it in a way 3-dimensional manner.In this technique, there is no usage of lenses, unlike normal photography. Technically speaking, the visual (hologram) is an interference pattern of the light waves.

The Characteristics of a Hologram 

Here are some common characteristics of a real hologram.

• The entire process of making the hologram will be lensless.
• A holographic image is formed by freezing an image and reconstructing it with a laser on its way to your eye. 
• The holographic image will be true 3-dimensional. It will show depth, and parallax and continually change in perspective with the viewing angle. 
• Every part of a hologram contains the image of the whole object. You can cut off the corner of a hologram and still see the entire image through it.

How is it Different from a Photograph? 

Being 3-dimensional, Holograms show depth and you can view different perspectives of the image concerning your viewing angle. Whereas the photograph is 2- dimensional and doesn't change in perspective. 

On the technical side, a photograph preserves the intensity of light bouncing off the subject. A holograph preserves the intensity and direction of the light travel off the subject.

What are Fake Holograms? 

Fake holograms are 3D images created with the use of a special technology that tricks the eye into perceiving a 3D image, even though it is not actually there. 

These are not true holograms and do not share the characteristics of a real hologram. 

They are often used in marketing and advertising campaigns, and for edutainment purposes by trying to mimic the look and feel of a real hologram. 

The following are examples of fake holograms;

1. HoloFan 

In HoloFan, LED light strips are attached to a fan, upon rotating them with enough speed creates an illusion of an image due to the persistence of our vision. These LED lights are programable and we can change the images and even make videos with sound. HoloFan allows for a variety of applications, from 3D holographic displays to interactive gaming.

2. Cheoptics 

These devices work based on mirror reflections. There will be mirrors placed at appropriate angles to capture images or videos to make them look 3-Dimensional. These images can be viewed from all angles depending on the type of cheoptics used. Cheoptics is used in a variety of applications, including entertainment, interactive displays, advertising, and product demonstrations.

3. Staged Holograms / Pepper's Ghost

Staged Holograms / Pepper's Ghost is a special effect used in theater, concerts, and other live events to create the illusion of a three-dimensional object or person appearing on stage. 

In 1862, English scientist John Henry Pepper began popularizing the effect with a theatre demonstration. Over time hardware used has advanced but the overall concept remains the same. You must have seen Tupac and Michael Jackson coming alive in the stage shows, these are done using Pepper's ghost technique. 

They use thin transparent holographic sheets on which the image/video will be reflected. The holographic sheets are transparent but they can catch reflections. The holographic sheets, projectors, and screens are all concealed and placed in a particular way concerning the audience's viewing angle. 

4. Smoke Projection

Smoke projection is a special effects technique used to create a realistic projection of an image or video onto a wall of smoke or fog. It is often used in theater and film productions to turn a simple wall of smoke into a magical and dynamic display.

A curtain of smoke is generated by using a smoke machine and a projector is projected onto it to give a ghostly feel. Since it is smoke, the image dissipates very fast. Any other factors like the wind can also interrupt the projection so it has to be done in a controlled environment. 

5. Water Projection 

Water projection is a type of projection art that uses water as a screen or canvas. It involves projecting images onto a wall of water, creating a mesmerizing visual effect. 

Multiple water sprinklers are used to create a surface of mist. This mist acts as a projection surface. When projected onto it with high-intensity projectors, the light is deflected by the tiny water droplets hanging in the air, thus creating a 3D illusion. 

These images can be pre-recorded videos or live images controlled by a computer. Water projection is often used in live events, such as concerts, festivals, and theatrical performances, to create a unique and immersive experience for the audience.

6. Smart Glasses

These are glasses that superimpose digital elements over the real world, these are called Augmented reality but are often mentioned as a hologram. This type of AR has close visual representation with a hologram but this can be seen only by the wearer of the smart glass. 

The smart glass usually contains multiple sensors, depth cameras, mics, and speakers. Technology is rapidly evolving and all the big players are in the space. To name a few key ones: Hololens by Microsoft, Spectacles by Snap, Magic leap, Epson Moverio, Amazon echo frame, etc. 

7. Mixed Reality Illusion

A mixed reality illusion is a type of augmented reality that combines virtual elements with real-world objects to create a simulated experience. It is a combination of virtual and real elements that create an environment that is indistinguishable from reality. When the staged hologram is combined with other sorts of supporting displays. It adds even more depth and illusion to the user experience. These are usually done in big shows, and theatres and are usually choreographed with a performance. 

8. Hololamp 

A Hololamp is a device that projects 3D holographic images into the air. It uses a combination of light, optics, and sound to create a realistic 3D experience that can be adjusted according to the user’s preferences.

This is a glasses-free and hands-free device which projects a 2D image in a way with great depth of field to produce the illusion of 3D. The way it achieves this illusion is by tracking the user's face. The output is pretty impressive and grabs a lot of attention but it can be viewed only one person at a time. 

9. Light Field Displays (LFDs)

Light Field Displays are special displays that showcase images/videos which are naturally viewable in 3D full color real-time that don't require the user to wear glass. This can have several people around the display, each person will be able to view from a slightly different viewpoint, depending on their position.

The following are some of the hardware in the industry that uses LFD technology.  

• Looking Glass 

This is developed by Looking Glass Factory. They use a proprietary light field technology to produce the desired effect. Around 100 views of a single 3D scene are stored from different angles so that people around can have a look simultaneously without the need for any phones or headsets. 

• Portl 

This has very little to do with a hologram but it is often called a hologram or holoportation. It is streaming live or pre-recorded video in human size from any part of the world and is shown on a transparent LCD screen.

• Google - Project Starline 

As of 2021, this is something Google is experimenting with and not available to the public. At some point in time, people will say this is a hologram but actually, it's not. This is a combination of computer vision, machine learning, spatial audio, real-time compression, and light field display to create a sense of volume and depth.

So how close are we to achieving a hologram like in the movies? 

As of 2021, the Volumetric display is by far the most advanced hologram we have achieved which is closer to the one in Starwars. The research team has figured out how to draw tiny screenless, free-floating objects in space. This can also show simple animation and also interactable. They are not a reflection or a mirage. They are actual physical objects floating in thin air. In this scenario, we can have a group of people standing around the display and everyone can view it from their perspective simultaneously. 

Final Thoughts

A real hologram may not meet all your needs most of the time, so it will be wise to use fake holographic solutions instead. You can use whichever solution is feasible for you. There is no right or wrong here.

Fake holograms can be used to create interactive experiences and provide immersive visuals for events or presentations. They are relatively cost-effective and can be used in a variety of contexts. As technology continues to develop and improve, fake holograms may become a more common sight in our lives.