Turn on the flashlight app on your smartphone and hold it in one hand with the hologram in your other hand. We’ll do another post some time about that!) Viewing holograms with a smartphoneĪ really exciting way we use to show off our reflection holograms at LitiHolo is to use the flashlight built into every smartphone. (There is another category of holograms called Rainbow Holograms, which were invented by Stephen Benton, and are almost a hybrid between transmission and reflection holograms. Thus a white light illumination source like a spot light or even sunlight can replay clear images (and even full-color images). As a result, the fringes are almost like multiple layers within the film that can filter out different wavelengths, and only replay the colors needed for the image, allowing the non-diffracted colors to simply pass through the film unaffected. Reflection holograms capture a laser light interference pattern very similar to transmission holograms, but the recorded fringes are oriented parallel to the surface of the film. On the other hand, “reflection” holograms have the light source coming from the front side of the holograms, with the reconstructed image “reflecting” back off the surface of the film. These recorded fringes are great at creating diffracted images that reconstruct the original wavefront, but they are very poor at filtering different wavelengths (or colors) of light, so replaying these holograms with white light creates a significant chromatic blur. For these holograms, the captured interference pattern of light forms “fringes” recorded in the film that are oriented perpendicular to the film’s surface. The laser light for replaying the images comes from the back of the hologram and the resulting image wavefront is transmitted through the film to be viewed from the front. Let’s Get Technical Source: Holographic Imaging, Benton.įrom a technical standpoint, the holograms that are only laser viewable are often called “transmission” holograms. Diffuse lighting (cloudy days or big fluorescent lighting panels) will still show an image, but the lack of “directionality” means the hologram is trying to create a replay image for every point on the source, and the result gets less clear for images that are deeper. Sunlight or a spot light are the best for viewing these holograms, as they are brighter and clearer with a source that is more “directional”. While they are still created with laser light, the structure of the captured holograms allows them to also be viewed without a laser, using more ordinary light sources. Reflection holograms are a special category of holograms that are visible using what is often referred to as “white light”. And while most holograms are made with laser light, capturing and replaying the full 3D image wavefront, did you know that some holograms can be viewed with an ordinary spot light or even sunlight? Reflection Holograms Holograms are amazing to look at! How can a flat piece of film create images that have such depth? You can literally “look around” the captured image and see different sides from different angles, even seeing areas that were hidden from a different direction. Made with the LitiHolo Hologram Kit and the Reflection Hologram Upgrade. Share on Facebook Share on Twitter Share on Pinterest Share on Reddit Reflection hologram viewed in sunlight.
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