Dead Simple Hologram Effect

We’ve all seen holograms in movies, and occasionally we see various versions of the effect in real life. The idea of having a fully three-dimensional image projected magically into space is appealing, but we haven’t quite mastered it yet. [Steven] hasn’t let that stop him, though. He’s built himself a very simple device to display a sort of hologram.

His display relies on reflections. The core of the unit is a normal flat screen LCD monitor laid on its back. The other component looks like a four-sided pyramid with the top cut off. The pyramid is made from clear plastic transparency sheets, held together with scotch tape. It’s placed on top of the LCD with the narrow end facing down.

[Steven] then used the open source Blender program to design a few 3D animations. Examples include a pterodactyl flying and an approximation of the classic Princess Leia hologram from Star Wars Episode 4. The LCD screen displays the animation from four different angles at once. The images are displayed up and onto the transparency sheet, which then get reflected to your eyes. The result is an image that looks almost as if it’s floating in space if viewed from the proper angle. If you move around the screen you can see the image from all four sides, which helps to sell the effect. Not bad for a few dollars worth of parts.

32 thoughts on “Dead Simple Hologram Effect

        1. i’m thinking of trying to use the bottom half of a mirascope to do it. with how those work the object would never display w/o the hole, the light would hit the screen before where it converges again making it appear as though it was there.

    1. You don’t need hundreds of images, you need one image warped into a circle (with a hole in the middle). The conical (not cylindrical) mirror would “unwarp” it. I’ve seen similar things online before, but I don’t have any links on-hand.

      1. There are a number of commercial projectors that use a similar transform. These ‘Short-throw’ projectors are designed to be mounted above white boards or touch sensitive boards. The project nearly straight down often relying on a reflector placed a few inches (6-12) out from the board.

      2. An anamorphic projection. ISTR some artist who made matching sets of distorted scupltures and mirrors that when arranged correctly and viewed from a specific point produced an undistorted image of the sculpture.

        Doing it with a simple cone would be somewhat easier. ;) Sort of a reverse of those 360 degree video cameras with software that can virtually pan around without moving the camera.

    2. How about spinning the reflector at speed and updating the image to show the view as-seen from the direction the mirror is facing.
      The update would need to be fast (FPS x number of viewing angles) but you would get a sort of all around view of the object. The image generator would also need to be able to calculate all the views as it would be a huge task to pre-load them all in.

  1. From the link “Here’s an easy to make hologram, one that shows four sides of an object.” This is a misuse of the word hologram, look it up, I did. This is a “3D” effect that has nothing to do with holography and yet another example of the casual misuse of a technical term which has been diluted by pop culture.

    1. Hmm… I mention out that it’s not strictly speaking a hologram in the video description but I see I didn’t put it on my webpage. It’s there now. But though it’s a misuse, it is what Pepper’s ghost has become known as in popular culture and even the companies that do it on stage. I wouldn’t doubt if there’s eventually an alternate definition in the dictionary.

    2. I’m making a drinking game out how far I have to scroll down a page on holograms before someone points out that the commonly accepted usage of the word isn’t technically correct. I expect to die of alcohol poisoning shortly.

  2. A simple way to make an effective hologram is a piece of glass angled at 45 degrees, spinning 360 degrees. An image is projected up in a similar fashion, but is timed to the angle of the glass. If spun a minimum of 60 rpm, well balanced, anyone from looking from any direction perpendicular to the projection would see a unique image from their perspectivr.

    1. Like USCs spinning mirror display. Not sure it’s simple necessarily, but the effect is great. They’ve got it spinning and projecting at a few hundred rpm I believe. The timing on the projection must’ve been tricky!

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