Summon the Jedi!

Princess Leia’s holographic message

“Help me, Obi-Wan Kenobi, you’re my only hope *static* Help me, Obi-Wan Kenobi, you’re my only hope.” ― Princess Leia’s holographic message to Obi-Wan Kenobi in ‘Star Wars: Episode IV’

My love for holograms starts predictably with the Iron Man series. It is the de facto example I give whenever I have to explain what they are. I’d love to have given a Star Wars example, however, contrary to my presumptions, most people I know haven’t really seen/followed Star Wars (Or maybe I’m hanging out with the wrong people then…That’s a discussion for a later time).

We’ve all seen holograms in the Star Wars series, Iron Man, even Harry Potter shows us some instances of this mixed reality. Holograms, once they become a thing of everyday life, will definitely reinforce my faith in humanity’s ability to make magical things. We are already seeing glimpses of that reality with the now defunct Google Glass project and the awesome Microsoft Hololens. I am not completely convinced with the idea of head mounted displays for mixed reality but I could be wrong; maybe someday we could embed mixed reality devices through contact lenses. Better yet, future generations are born with mixed reality embedded within and in that sense it becomes their only reality.

The beginning

While assisting Dr. Sarah Kenderdine on the Domelab project at the CSMVS Museum in Mumbai I was introduced to Mr. Anupam Sah (I will refer to him as Sir henceforth) who heads the Heritage Conservation Lab at the Museum. Honestly, it is an amazing space to be in. It is a lab full of conservation professionals, historians and scientists working meticulously and with such intense focus that the space feels almost sacred to the geek in me.

The Lab

Sir and I began to talk about what we did, about the upcoming exhibition of curated artifacts that the lab had conserved, the problems that emerged and what I could do to help. Those who know me from grad school know my love for data visualization and I was pretty sure from the beginning that there would be a dataviz element in there. This, however, was secondary. The main problem that emerged- a fairly common one in museum exhibits- was the lack of physical space. Museums, on an average, are able to display only 5% of the articles they withhold of which many keep moving between galleries and other museums. How does one show artifacts when there is no place to show them? One instinct was to have a simple picture gallery on a TV screen, the advantages being the high resolution of the screen and the ease of setting up such a system. A 2D surface works well for viewing images or a painting at a distance, but not all artifacts are of the same nature. What happens to 3D objects then? I thought if we can’t re-create the real object, we can always create an illusion of it. That’s when we came up with the idea of creating holograms of objects that cannot be a part of the exhibition but we would have liked them to be.

How to

A Mobile Phone Hologram (DIY)

Holography as a concept, invented by the Hungarian scientist Dennis Gabor, is more than half a decade old. I recalled having seen this DIY project on Youtube about small holograms for the smartphone made with transparent OHP sheets. Essentially, the one I used for the exhibition works on a similar concept of internal reflection of 4 images/videos in synchronization on an acrylic prism; a reconstructed view of a scene in a single plane of light.

How holograms work — Schematic

I don’t want to explain the details of how holograms work, but for those curious enough, here are a few links to get started:http://science.howstuffworks.com/hologram.htmhttp://holocenter.org/what-is-holographyhttps://en.wikipedia.org/wiki/Holography

While working on this project I was in the middle of Elon Musk’s biography and had finished ‘Jugaad Innovation’, both of which emphasize the idea of doing more with less. I was inclined towards the same. The challenge was to create these holograms with as little equipment and resources as possible.

A little bit of common sense, the will to get things done, and a belief that we can figure this out are the most important and often the only qualities needed to do anything.

Of course, anything that has been done can be done better and therein lies the challenge for a novice. Here I was, given this blank canvas, and I had decided to build holograms for a very prominent museum in the country without any experience whatsoever. Best decision ever, right?

Honestly, I had my doubts. I believe that a little bit of common sense, the will to get things done and a belief that we can figure this out are the most important and often the only qualities needed to do anything.

The goal was to create holograms of around 20 objects from different time periods, made of different materials and from different parts of the country. I began with the idea of taking photographs of four faces of an object since we were using a four sided prism. One faces an obvious problem with this approach; static images of an object reflected on the prism create an illusion of 3 dimensions. However, they fail to show the observer interesting details at the edges of these surfaces and we quickly decided to use videos to mitigate these ‘edge cases’. The first thought was to use four cameras facing four sides of the object and rotate the object in a full circle. The cameras would capture four points of view of the rotation simultaneously and a single video would be generated in post processing. However, the cameras and the lenses we had access to were all disparate, which meant a lot of efforts in post processing, not to mention the rent we would have to pay for the equipment. Remember the challenge I had given myself? Yes the ‘do more with less’ one. I had wanted to use a Canon 5D Mark IV for shooting the videos and renting three out (the museum had one in its store) for a few weeks would turn out to be an expensive affair.

Using four cameras to capture a single hologram image.

Eureka!

Instead of using four cameras, we decided to use only one and rotate the object at a constant RPM. I could always generate four videos in post processing from a single video.

The museum wanted to buy a rotating table and this was an opportune moment. We also had access to one Canon 5D Mark IV that belonged to the museum. So essentially shooting the video would be free for us compared to the lakhs we’d earlier have to spend. This was great. The rotating table was scheduled to arrive after a few weeks which gave us time to plan. We figured out the optimum position, lighting, a green screen and other details. A trial run was done with one of the objects and it seemed to be a legit workaround. The conservation lab also got time to figure out a list of objects to create holograms for and obtain permissions for videography. We made a three day schedule for the videography once the rotating table arrived.

Using a single camera and a rotating table to achieve the same holographic image

All videos were shot at a constant 1 RPM. Once the videos were shot, it was time for post processing. The green screen background was erased.

The setup

Capturing for the hologram

The videos were a 360 degree rotation of the object. The timeframe of each video was split into four parts, i.e 15 seconds. Four videos were generated from the base video such that each video looked like it it began from one of the four splits and ended at the same position, thus creating an illusion of looking from a specific point of view. The four videos were composed into a single video which were used to generate the holograms.

Final Holograms — This was shot with a low res smartphone camera

Afterthought

We tend to judge our experiences as a combination of senses and not in parts; food tastes better when the room temperature is just right.

Like any project, this too has its limitations. We had to discard a few initial ideas due to time and cost constraints, including the creation of an interface on a tablet that could be used to navigate through the holograms. Despite efforts to get the highest resolution possible, creating crisp holograms economically is still a farfetched dream. It would require at least a thousand times higher resolution to generate a perfect holographic image. In the current case, I used a standard 40 inch TV screen that the museum owned to display the reflection, so there were concerns with its resolution. After some reading, I realized that any kind of interaction is always more than what meets the eye. A good experience typically engages multiple senses. A social scientist named Russ Neuman conducted an experiment on an audience response to display quality. He set up two identical displays and asked a group of participants to view the displays and judge their quality. The only difference between the two displays was that one of the display set ups used a higher quality sound system while the other one used a standard one. Results of the experiment showed that many of the subjects reported a considerably better picture quality in the case where the sound quality was better. Both displays were the same. We tend to judge our experiences as a combination of senses and not in parts; food tastes better when the room temperature is just right.

Holographic interfaces seem like a strong contender for the future of Human-Computer Interaction (HCI), although I am of the opinion that different contexts beg different interfaces. With the advancement in voice recognition and cognition, it seems like voice interfaces will grab a significant chunk of the modes in which human beings interact with machines. What is more convenient than pointing to an object and commanding it to be at your service, like a genie in a bottle? The best user interface would be no user interface. Voice interface agents like Siri, Alexa, Google Assistant, Cortana among others have already begun to create their personalities. In the future these personalities would be customized for every person based on the user’s age, gender, nationality, social constructs, relationships, etc. These digital personalities might start taking a physical form and maybe you will have holograms of Siri or Cortana running through your entire house asking to run small errands or read out news curated for you.

Holograms might just be one of those rare moments at the intersection of art and technology that truly inspire thought; a form of mixed reality that is extremely engaging, and the idea of which is almost magical and poetic in that it enables a seamless interaction between the real and the virtual, turning us into wizards in real life. It is a more beautiful reality than VR while much more difficult to achieve. And like most things in life, this too is a clever illusion.

Acknowledgements

I am grateful to Mr. Anupam Sah for giving me this opportunity. Thank you Nidhi Shah, Renuka M, Onkar Abhyankar, Rajesh Poojari and the staff at the CSMVS Museum for their support.

P.S: The holograms can be seen till the November 1st, 2016 in the Premchand Roychand Gallery at the CSMVS Museum. They are a part of the ongoing CITI ConserveArte Exhibition.

References

• Instructables
• Being Digital — Nicholas Negroponte

Freebies! Download a prism template to create your own hologram:PDF (illustrator editable)SVGRule of thumb: For a 5" smartphone, scale each part such that the shortest side measures 1cm . Always scale with the same aspect ratio i.e. Shift+Scale

Now that you feel wiser, here’s a picture of Master Yoda…