TikTok is full of videos on wellness, viral tech life hacks (which may not work), and choreographed dance routines, but one of the coolest viral videos right now is a tutorial on a DIY trick that shows you to project a 3D hologram illusion from your phone. In this video, which has 3.2 million views at the time of writing, Tiktokker reddnea uses a smartphone and some household items to project a YouTube video of animals into what appears to be a 3D hologram.
However, the projection isn't a hologram you can touch. It's an optical illusion that is essentially a scaled-down version of a 19th-century parlor trick, which is still used today at theme parks, theatres, and concerts. But how do they do it? And how does it work? There are several ways to do this cool trick. While Mr.Hacker on YouTube provides a detailed tutorial on several methods you can try, we'll focus on reddnea's viral TikTok video, as it's one of the most straightforward and cost-effective methods we've seen.
How to project a 3D hologram illusion with your phone
What you need:
- A smartphone (like the iPhone 17)
- A sheet of transparent plastic film
- A clear square or rectangular glass dish (roughly the size of your phone)
- Tape
- A non-permanent marker pen
- Scissors
First, turn your glass dish upside down so the bottom is facing up. Next, place your phone face down at the center of the container's bottom; it's fine if the top and bottom of your phone protrude from the edges a little bit, as long as your screen fits. The good news is that even if you have one of the worst smartphones ever made, you can still perform this trick.
Next, ensure your plastic sheet is sturdy enough that it won't collapse in on itself. You also want to ensure your sheet is as unblemished and smooth as possible. Cut your sheet to the size of the marks you made so that it comfortably fits into your dish at a 45-degree angle, using a small piece of tape at the top and bottom to secure it.
With your plastic sheet inside your glass dish, turn it upside down again, then rotate it so the plastic is sloping down toward the person viewing. Now for the cool bit. Find a 3D hologram video online — like this one – and play it full screen on your phone, ensuring your brightness is turned up to maximum. Place your phone screen down on the dish as you did before, turn off the lights, and you should see the video projected as a 3D hologram inside the dish.
How the 3D hologram illusion phone trick works
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This optical illusion dates back to the 19th century, and it's commonly known as Pepper's Ghost. While it makes for a real cool trick at your house, it's also used in theatre productions, haunted houses, theme parks (like Disneyland's Haunted Mansion ride), and in concerts. Real holograms, on the other hand, are 3D images created by the interference of light beams and, therefore, are able to be viewed from any angle without the need for special screens, lenses, or props.
With the phone trick, the "hologram" you see is actually a reflection of the image from your phone screen. When you look straight at a clear piece of glass, like a window, you'll see your reflection, making it appear as if you're on the other side, but you can still see the background. In simple terms, that's because the clear surface (in this case glass) reflects some light and lets other light pass through it and the human eye combines both into one scene.
So, when you add the angled plastic sheet into your glass dish and play a holographic video, the video image is reflected off the 45-degree angled transparent sheet and into your eyes, but you're still able to see the real background through it as the sheet is clear — meaning it acts as a sort of mirror and window in one. As your brain combines the reflection and background into one scene, it perceives the image as floating. There's even an episode of "The Magic School Bus" dedicated to showing the science behind this trick.