Deceiving Art: A Guide to Stereograms
We’ve all seen those games or puzzles that seem to play tricks on our eyes. They seem like one thing at first, but after staring hard enough, the image seems to change right before us! Ever wondered how that works? These types of visual tricks are called optical illusions. When we receive information from our eyes, the brain tries to match it with something that it knows is true. For example, if we saw a man with three legs, we’d probably rub our eyes and think that we’re not seeing correctly! Optical illusions use certain techniques that manipulate shapes, depth, color, and perception, to trick our brains. As the brain tries to process the information as best as it can, it is sometimes fooled into creating an output that is untrue in real life, but it makes the most sense to us. When we watch a 3-D movie, we know that the actors and special effects are not really there in the movie theater. However, if we perceive a 3-D train rushing right at us, we automatically flinch or duck!
One type of optical illusion is known as stereograms. A stereogram use two similar side-by-side images that are adjusted slightly different for each eye. When you view them together, they seem to overlap and form a three-dimensional image. Originally people had to use a device called a stereoscope to see the final image. A related example is the types of two-dimensional images that contain a scrambled jumble of messy, confusing colors. When a viewer stares at them for a very long time, a clear 3D image appears from beyond the mess! Although we also refer to these images as stereograms, they are actually autostereograms since they only comprise of a single image. Autostereograms are made digitally with computer software by layering two images over each other. Some stereograms combine two overlapping images that are in shades of red and blue respectively. When viewed with 3-D glasses, the pictures combine in our brains to form a three-dimensional effect. Viewing stereograms properly sometimes takes a bit of practice. One way is to put your nose to the stereogram, and with your eyes crossed or unfocused, move back away from the image slowly. Autostereograms also take a bit of time. Viewers typically stare at the center of the image with their eyes unfocused for several minutes before noticing the hidden 3-D picture. As you practice, you will notice that you are able to find the hidden images more and more easily. Remember to take a break after every couple of pictures so that your eyes and head don’t hurt. Now have a look at the following resources to learn about stereograms , and then see try a few examples to see how easily the brain can be tricked.
Image: Courtesy of Wikipedia
- How Our Eyes Create Stereovision
- How to Make Digital Stereograms
- An Explanation of Stereogram Viewing Methods
- K 3-12 Lesson Plan on Optical Illusions and the Brain (PDF)
- View Some Stereograms for Yourself!
- Learn to Create a Digital Stereogram On A Computer
- All About Stereoscopy and How it Works
- Step-by-Step Instructions for Viewing 3D Stereograms
- Stereograms with Randomly Generated Patterns
- What Is a Random Dot Stereogram?
- Build Your Own Stereograms with an Online Generator
- Winter-Themed Stereogram Images
- An Explanation of Stereograms for Kids
- A Quick Introduction to Autostereograms
- View Some Stereograms with Special Effects
- Optical Perception and the Effect of Stereograms
- What Are Stereoscopes and How Do They Work?
- How to Build a Stereoscope at Home
- Examples of Old-Fashioned Stereoscopes and Related Devices
- A History of Stereoscopes and 3-D Images
- Stereograms and Other Optical Illusions with Solutions
- A Selection of Photographic Stereograms
- Why Are Some People Unable to See Stereograms Properly?
- Stereograms to View with 3-D Glasses
- Why Do Stereograms Produce the Perception of 3-D Images?
- A Middle School Class Handout on Stereograms (PDF)
- Practice Viewing Some Photographic Stereograms
- Print Some Fun Free Stereograms
- Autostereogram Images and Activities
- The Science Behind How Autostereograms Trick the Brain
- Vision, Depth Perception, and Stereograms (PPT)
- How the Brain Interprets 3-D Images
- Class Activity: Make Your Own 3-D Glasses!
- Autostereograms from Disney’s The Lion King
- Tips for Viewing Parallel Stereo Images
- Learn How Our Brains View Images in 3-D
- Different Methods and Devices for Viewing Stereograms
- A Gallery of Color Stereogram Images
- A Tutorial on Creating Stereo Photographs
- Styles of Stereo Images and Viewing Devices
About the Author:
Clare Tames is a self-employed freelance graphic designer, formidable cook, and avid reader. She written on contemporary and classical art in various print publications, and is just now beginning a writing career online. She works out of her home office in California, where her two children attend high school.