Digital Cameras: Everything Is a Click Away
In the classic Disney movie "Tron," a computer hacker is captured by a rogue super-computer, cut into digital cubes and sucked by a camera-like device inside the machine where he must battle for his life against electronic adversaries.
A digital camera owner displays the back of a digital camera with its liquid crystal screen showing his own image being captured. Once the shutter is snapped, images are stored on memory devices, such as floppy disks so that users can review the photographs immediately. (AP/Wide World Photos/Paul Sakuma)
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Today's digital cameras can reduce you to something even smaller than Tron's digital cubes: a little pixel. But, those little pixels—and digital imagery—have substantially changed our lives. And virtual imagery—from newspapers, to computers, to even cell phones—has been burned into the everyday fabric of our pop culture. By some accounts, teenagers will encounter more than 1,000 camera images each day. The encounters can range from the flurry of pictures that pop up on your Web browser, to the nightly news from Iraq, to your student I.D.
In addition to all the cool things digital cameras allow us to do, they also have fundamentally changed the way we relate to our world. We are becoming an image-based society, said Joshua Halberstam, an instructor at the Columbia University Teachers College. Back when writing was supreme and photography was just a twinkle in somebody's eye, writers ruled. Today, the picture tells the story. "One-hundred years ago, a person might say: 'I feel like a character in a novel,' " Halberstam said. "Now they say: 'I feel like a character in a movie.' "
But, the technology didn't just fall out of Bill Gates' back pocket last fall. In fact, the origins of photography can be traced back to the early 1400s and the artistic techniques developed by Italian architect Filippo Brunelleschi. Brunelleschi and others developed the system of single-point perspective, which provided painters with a method for depicting three-dimensional space on a flat surface. It is still used by painters today. Based on the notion of a single observation point, lines appear to recede into the distance by converging on a fixed point on the horizon, called the vanishing point.
To understand the technology behind digital cameras, you must first know what photography is: any method for producing lasting images by means of a chemical—or electronic—reaction that occurs when light hits a specially prepared surface. The technology for modern photography was laid down in the early 1800s with advances in chemistry and optics.
Photography: "Writing With Light"
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A daguerreotype of a couple. Made around 1850 in Cleveland, Ohio. (The Daguerreian Society)
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An essential element in the invention of photography was the under-
standing that certain substances react to light. More than 2,000 years ago, the ancient Phoenicians knew that a certain snail, the purpura, left a yellow slime trail that turned purple when exposed to sunlight. But how did we get from snail slime to Kodak? It took until 1800 when an English chemist, Thomas Wedgwood, produced images of leaves on leather that he had treated with silver salts. A Frenchman, Louis Jacques Mande' Daguerre, in 1837 developed a method to "fix" the image to keep it from turning black—voila the daguerreotype (View the History of Photography). A daguerreotype is a copper plate coated with silver iodide which is then exposed briefly to light. After developing, the resulting image is "fixed," or made permanent by washing away the remaining silver iodide with a solution of warm water and table salt.
In 1888, modern photography was born when inventor George Eastman perfected his Kodak camera, which was loaded with a roll of paper film. The concept of a snapshot, a hunting term for shooting from the hip, was born. Advances quickly followed in lens, and plastic film replaced
the old Kodak paper.
Behind the Shutter
Unlike film-based photo-
raphy, which relies on a chemical process to capture and store images, a digital camera uses a CCD (charge coupled device), which is a light sensitive computer chip that captures images and stores them on internal or removable memory.
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Fast-forward to the 1950s and the approach of television. Digital cameras are the cousins of the technology that records and broadcasts the images on MTV. Both use a CCD (Charged Coupled Device) to sense light color and intensity, which are then transmitted to special processors that interpret and capture the images.
Computer manufacturer Texas Instruments patented a filmless electronic camera in 1972, and was the first to do so. In August 1981, Sony released the Sony Mavica electronic still camera, the first commercial electronic camera. Images were recorded onto a mini-disc and then put into a video reader. However, the early Mavica cannot be considered a true digital camera even though it started the digital camera revolution. It was a video camera that took video freeze-frames. A few years later Kodak invented the world's first megapixel sensor, capable of recording 1.4 million pixels that could produce a 5-x-7-inch photo-quality print.
How It Works
Instead of film behind the shutter, a digital camera contains imaging arrays onto which the lens focuses light. On these arrays, or chips, are the CCDs. When the CCDs are struck by light, they emit an electrical charge which is turned into binary information by the camera's processor. This digital (or binary) information—the ones and zeros of computer language—allows the mini-computer inside the camera to translate the color and brightness into a machine code that can produce a photograph.
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A CCD is an array of photosensitive elements, each one of which generates photoelectrons in response to light and stores them as a small bucket of charge. (Brunel University, UK)
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A Really Big Deal?
The QX3™ digital computer microscope
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So what's the big deal? Haven't we just traded a silicon chip for some photographic film? Not exactly. For one thing, the results are immediate—there is no waiting around for the shots to be developed. For another, the images can be shared without the use of paper. The real magic of digital cameras, however, is in the application. A digital camera is smaller and more versatile. There are similarities; for example, both digital and film cameras still capture their images through an optical lens. But, no one would ever stick an old 35mm SLR into their pocket, jump onto a Six-Flags rollercoaster and then whip out the camera to take surprise shots on the underside of a loop-the-loop. Digital cameras are small enough to do that and perform other hijinks as well, like taking microscopic scenes from inside the human body or enlarging a drop of blood in biology.
Digital cameras also are really good as microscopes. A few years ago, computer-chip maker Intel launched the Play QX3™ Computer Microscope. Even though the device has "play" in its name, it is a real working microscope, said Randy Bell, an assistant professor of science education at the Curry School
Center for Technology and Teacher Education, University of Virginia.
Here's what a strand of hair looks like under a digital microscope.
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One of the biggest hurdles in biology class is for students to manipulate the microscope lens enough to allow them to see tiny creatures in the device. With the QX, students now can look at magnified images on a computer screen rather than squinting through a smudged eye piece. "We had a high school student come up and say that he had been in school for years and had never seen anything but air bubbles until they had the QX microscope," Bell said. "With the click of a button you can save an image, a video clip or engage in time lapse photography. You can show crystals growing or butterflies emerging."
The real magic behind the QX is the active pixel sensor-CMOS, or "camera on a chip" video technology. It is used to shrink the on-board digital camera into a single 2 1/2-inch diameter circuit board that fits snugly within the microscope body.
Olympus MIC-D Digital Microscope. Uses USB technology to produce live images and digital viewable on a computer monitor.
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Teachers at the center continue to be amazed at how engaged students become when they use the QX, Bell said. Pond ooze never seemed so interesting.
CMOS (pronounced see-moss) is short for complementary metal oxide semiconductor. The technology is not new—it has been around for several decades. CMOS is a widely used type of semiconductor. CMOS semiconductors use both NMOS (negative polarity) and PMOS (positive polarity) circuits. Because only one of the circuit types is on at any given time, CMOS chips require less power than chips using just one type of transistor. Personal computers also contain a small amount of battery-powered CMOS memory to hold the date, time, and system setup parameters. See how a CMOS transistor works!
Olympus recently introduced the Olympus MIC-D Digital Microscope, a slightly higher-end device with a broader spectrum of applications. View some samples of their work.
.: A Word about Pixels :.
So what's a pixel? You will hear this word—which means picture element—frequently when talking about digital imagery. If you were to take a digital picture and blow it up enough, you would see little color squares. Those are pixels. They are an optical effect created by the CCDs and they have a horizontal and vertical size measured in microns. A micron is the metric measurement equal to one millionth of a meter, or 0.00003937 inch. The pixel is actually the result of the CCD telling the optical software how much light struck it. The more pixels, the higher the resolution in a photo.
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To Outer Space
Let's move from inner space to outer space, as in planets. Meade's ETX telescope integrates digital imaging with its Autostar Computer Controller. When hunting for objects in the night sky, one of the biggest problems is finding the right one. With Autostar, the astronomer punches the GO TO pushbutton on the hand-held controller and watches as the telescope automatically transits to the object and places it in the field of view. The effect of Autostar is to bring objects that were previously unreachable easily within reach. Autostar has a 30,000-object database. View some sample moon pictures.
After finding the celestial body, a simple adapter makes it easier to photograph it with a digital camera. This is where the digital camera's instant results really come into play. Taking pictures of the night sky can be tricky even for professional photographers. The challenge is nailing the right exposure. With film, it's hard to tell if you got the exposure right. With digital, you see the image (or non-image) immediately and adjust accordingly. Students who never even saw a close-up of Saturn before are now able to take telescopic pictures of it with the new technology, said Bell.
For fun, there are digital binoculars. It's the 007-type marriage of a pair of simple binoculars with a tiny digital camera. Point, shoot and take a picture. Digital Blue's Zoomshot Digital Snapshot Binoculars offers 8x magnification, video clips and enough memory to store up to 100 still images at a time.
Gazing At the Crystal Ball
In the future, cameras generally will become cheaper, faster and much better. The bigger challenge may be in how we change in relation to the almost ubiquitous digital cameras. In Japan, 80% of all cell phones have cameras in them, said Columbia University's Halberstam. Columbia is consulting with Olympus on the development of Envision Your World online curriculum program. It is targeted for grades 4-6.
"The difference is that we will be able to capture our experiences in digital photography that we never did before," Halberstam says. Imagine an art teacher who wants you to show how you made a painting and then uses a series of digital photographs to help correct your technique. Instead of an essay, soon students may be asked to present a photo montage of how they spent their summer vacation. Instead of pen pals, we could start having global photo pals where the language barrier is broken by the simple exchange of photographs.
Is it far-out like Star Trek? Maybe. But these are all examples of emerging technology applications that are just around the corner.
XtraReal People
Name: Joshua Halberstam
Age: 57
Title: Adjunct Professor
Affiliation: Teachers College, New York's Columbia University Institute of Learning Technologies.
His real job: "I don't have a "typical" job. For many years I was a college professor, and now I do that part-time. The good news for me is that I don't have a structured day with predefined hours the way people do in most professions. But not having a structured day is also the bad news. It means you have to be disciplined and organized."
Why he chose this career: "My professional training is in philosophy, which deals mostly with abstract ideas. Interestingly, some of the most exciting philosophical questions of recent years emerge from developments in technology. One obvious example is artificial intelligence and the question of how machine and human thinking are alike and differ. I'm very curious about how the mind works and technology is providing some of the main clues."
School: B.A. Philosophy, 1968, from the City University of New York—Brooklyn College; PhD, Philosophy, New York University, 1978.
Was he a math/science wiz in school? "I wasn't especially drawn to math and sciences in high school. But if I went back to high school now, I'd take those subjects much more seriously. Grown-ups constantly tell their students and children that if you don't pay attention when you're younger, it's really hard to study this material when you're older. Guess what? They're right. If you aren't comfortable with math and science, the world will whiz by you and you won't understand what's passing you by."
What he does for fun: Writing, listening to all sorts of music from classical to rock, and computer chess. But, "the distinction between work and play is artificial. Whoever made up the word "homework" did us all a huge disservice—who wants to work at home? If they called it "homeplay" we'd have an entirely different attitude."
Favorite sport: Pick-up basketball. "but I'm slower now and rely too much on my outside shot which never was that great."
Advice: It's not a field that will necessarily reap fame and fortune. Unlike athletes, movie stars and politicians, scientists won't find a guest spot hosting MTV or probably won't make as much money as successful lawyers or investment bankers. "But what you will do is so interesting and important; we desperately need more first-rate scientists and technologists. And for those of you with an artistic bent, fields like digital photography offer a fascinating blend of art and engineering."
Tips: "You've probably all figured this out already, but you do your best learning when you care about the subject you're studying. Don't wait until your high school graduation day to hear a speech about how important it is to go with your passion. Start now. One of the big differences between young people who succeed and those who don't is sustaining curiosity. Take classes that are challenging, not just the easy ones."
Gazing at the crystal ball: "I see people everywhere whipping out their digital cameras and shooting away. Now, we not only can capture our experiences just about whenever we want to, but we can easily share those experiences digitally immediately and around the globe. I do think digital photography will radically change the way people around the world communicate, but we have to remember we're just at the beginning of this technology."
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XtraReal People
Name: Yasuo Asakura
Age: 48
Title: Product Director
Affiliation: Research & Development Dept., Imaging System Group, Olympus Corp., Japan.
His real job: Mr. Asakura has developed both film and digital cameras for Olympus, including the E-1 all-digital professional SLR camera for which he received the imaging industry's technical achievement award earlier this year. "My job consists mainly of four areas. The first one is making strategic plans for the future product line-up and developing the concept and specs of each product. The second one is the management of the development process of the planned cameras. In that position, the Product Director plays the roll of a conductor or a captain of the development team. The third one is to convey our messages that we put in the product correctly to the customers. And finally, the most important one is the management of future technology developments."
Why he chose this career: "When I was a child, my father used to take pictures of my family with his Rolleiflex 6x6 Brownie camera. I remember the photos were black and white and the prints were square. I am not sure how much this experience affected my career, but I am sure I have inherited his gene as photo hobbyist. The moment I chose to become a camera engineer was later as I started to study mechanical engineering at the university."
School: Sophia University, 1979, Science and Engineering undergraduate course, Mechanical Engineering Dept; Sophia University, Master Course, 1981, Science and Engineering.
Was he a math/science wiz in school?: "Yes, math and science (physics) were my favorites. I also was interested in history and art in my high school days—especially ancient history. I used to draw pictures in the suburbs of Hiroshima, where I grew up, in a sketchbook for watercolors."
What he does for fun: "I like climbing and photo shooting very much. Grand and beautiful mountain views, winter mountains, I love all these things and I spent most of my holidays on the mountains when I was in (college)."
Favorite sport: "I love skiing and fishing. It is very interesting to learn the history of the technologies applied to the equipment."
Advice: "I would recommend that you try to thoroughly experience anything that you feel interested in. Even though it looks as if it is not related to your future career, the experience will lead to expanding your thinking."
Tips: "Science and engineering classes are probably the most important. As a scientist, "you also need to deal with nature and physical phenomenon. Faulty theory or calculation does not yield good results. Words of excuse do not make sense in this field. So, dig into math and science; that will be the basis of your future career."
Gazing at the crystal ball: "I can clearly see tiny camera chips. I can see ultra high-resolution small cameras for people who take pictures for their businesses and hobbies. Cameras can record not only what you can see, but also what you can not see—or what you can see but can not recognize. In this digital age, faster and more sensitive cameras that were not possible in the film age have been realized. The cameras which captured athletes in the Athens' Olympic Games gave us vivid faces and movements that we could not capture with our naked eyes. In terms of the burst rate, cameras are getting into the world beyond the reflexes of photographers, which may lead to capturing Henri Cartier-Bresson's (so-called) 'decisive moment.' "
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A Bit More
Ok, so all this talk about bits, bytes and pixels is giving you a bit of a headache. No problem. The truth is our brains aren't wired for digital anything. To the contrary, our perceptions are wired for analog technologies, which allows for continuous change rather than the discrete steps that digital offers.
Confused? Take a digital clock vs. an old-fashioned analog clock with a circular face, numbers around an outside ring and hands for hours, minutes and seconds. On the digital face, the clock will tell the time via an electronic read-out: 12:15 and 30 seconds, for example. But it's not very good at showing anything in between. With an analog clock, you can watch the sweep second hand smoothly spin around the dial as it moves from 12:14 to 12:15.
Probably the most obvious spot where the idea of digital steps comes into play is for digital camera resolution—which is measured by the number of pixels a camera can capture. It doesn't take a genius to figure out that the greater the number of pixels, the better the resolution. That's because no matter how much you enlarge a digital photo, the pixels will stay the same size relative to the full photo. Too big, and you get pixelated, which is generally bad because you see the individual pixels. Sort of like seeing just the individual trees and missing the overall shot of the forest.
A megapixel is a million pixels. Most consumer cameras are in the 3-to-5 megapixel range. At the upper end, you can get film-quality 8x10 prints from the digital shots, which print out on paper about the same quality as we've come to expect from film cameras.
Although our brains are not wired for digital, they are very good at processing visual information. The real value of these digital imaging devices is that they produce better pictures of reality for our eye/brain "computer" to process.
If you're interested in digital imagery, or just want to noodle around with some cool photographic stuff, try exploring some of the activities that offer real-world experiences.
A number of colleges have active research programs looking at digital imagery and school curriculum. Browse over to Columbia University's program. Start with Lesson 1 - Why We Invent - a sample lesson for the complete science curriculum.
Or just take a spin on a virtual microscope at Florida State University's Molecular Expressions Virtual Microscopy Web site. The virtual microscopes explore specimen focus, illumination intensity, and magnification; they operate essentially like real-life microscopes.
Check out the NSTEP Web site www.nationalstep.org and click on TechXplore, our program and competition that connects teams of students with scientists and high-tech companies to explore the world of technology. If you want to create a TechXplore team at your school to explore digital imagery, send an email to TechXplore@nationalstep.org.
Photography Links
DigiCam History Dot Com is a non-profit, educational site for digital camera enthusiasts.
The Michigan Photographic Historical Society was formed in 1972. The Web site offers information on old photographic equipment, images, photo literature, processes and techniques.
Photography Collections Online has a steadily growing digital image sampler and browsing resource for the vast photography holdings of George Eastman House.
PhotoGuide Japan offers a chronology of significant events and tidbits in the history of Japanese photography spanning from 1646 to present day.
Photography On-Line is a good site for historical photos and images of very early cameras.
The Photographic Historical Society is the first society devoted to photographic history and the preservation of photo antiques.
Rochester Institute of Technology, School of Photographic Arts and Sciences) offers an on-line exhibition which celebrates 100 years of photographic instruction at RIT. The exhibition consists of 259 pieces.
The Virginia Center for Digital History is best known for the award-winning multimedia project, The Valley of the Shadow: Two American Communities in the Civil War.
Resources
Center for Technology and Teacher Education is a cross-disciplinary group of faculty working together in the Curry School of Education at the University of Virginia.
Envision Your World is an online curriculum program designed to meet academic and technology standards for grades 4-6. The program allows students to investigate visual imagery, historical documents, and the process of invention through a series of hands-on activities and themed lessons.
Inventors Photography Timeline offers a great overview of the invention of photography and early cameras.
Photoxels offers an overview of the developmental stages of various camera models.
Wikipedia Encyclopedia of Inventions provides a free encyclopedia on the development and history of our pop culture.
Digital Imaging Glossary
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Analog: Comes from the word "analogous," which means "similar to." The transmitted signal--voice, video, or data--is analogous to the original signal. In telecommunications, it means telephone transmission and/or switching which is not digital.
Bit: One memory cell, one binary digit. A bit is the smallest piece of information that a computer can handle. It has only one of two values: either on or off, up or down.
Bitmap: Originally a bitmap was the image file using the on or off bit to produce a black or white pixel or dot. Now it generally refers to a graphic which is defined by specifying the colors of dots or pixels that make up the picture. It is also known as raster graphics. Common types of bitmap graphics are JPEG or TIFF.
BMP: Windows Bitmap file format was created by Microsoft® as the system standard image format.
CCD: Charged Coupled Device, a semiconductor device used to capture images, as in a digital camera.
CMD: Charge Modulated Device is an active pixel sensor (APS), using a pixel structure borrowed from CCD technology. Two transistors reside in each pixel producing a high fill factor. CMDs also use CMOS technologies to produce images.
CMOS: Complementary Metal-Oxide Semiconductor that converts light to electrical current—cheaper but noisier than a CCD.
Digital: The measurement and recording of continuously varying values of elements in the physical world, such as sound, light, temperature, etc., which correspond proportionally to values such as electronic voltage. These values are then converted into binary (1 and 0 or on and off) bits of information.
EXIF: A new storage compression file format used to store images on flash memory cards and digital cameras. Exif files contain either JPEG compressed files or uncompressed TIFF files, and can contain additional header information. (Also see TIFF and JPEG)
GUI: Pronounced Gooey, stands for Graphic User Interface. Refers to the computer interface with software in a user-friendly appearance.
"Jaggies": Slang term for the stair-stepped appearance of a curved or angled line in digital imaging. The smaller the pixels and the greater their number, the less apparent the "jaggies." (See pixelated).
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JPEG (Joint Photographic Experts Group): The de facto standard file type for image compression in digital imaging devices. JPEG uses areas of 8 x 8 pixels and compresses the information based on a set ratio.
Interpolation: The insertion of pixels into a digital image based on existing data. It is used to resize an image file to give an apparent increase in resolution.
Mega Pixel (or megapixel): The imaging term for an image sensor of one million pixels or more. The higher geometric pixel resolution sensors produce higher quality digital photographic images.
MMC Memory Card (Multi-Media Card): A type of solid-state memory card about the size of a postage stamp used in digital cameras and other electronic devices.
MPEG: Motion Picture Expert Group. The abbreviation is used to describe a compression format for digitized video images.
PDF (Portable Document Format): Adobe® Systems' cross-platform file type that allows images and text to be sent and viewed by many different computers.
Pixelated: The appearance of a digital image whose individual pixels are clearly discernible.
QuickTime: Developed by Apple Computer Inc., this is a standard for digital videos and streaming media. It provides the ability to record and view motion picture video with a digital camera.
Resolution: A measure of the level of detail in an image or a measure of the capability of a device to represent detail.
RGB (Red, Green, Blue): The color model of computer monitors and digital cameras. These primary colors are used to create all the colors seen on the monitor and saved in files. The color green is additionally used for contrast control.
TIFF: Tagged Information File Format is the file format developed for universal transfer between many digital imaging applications and devices.
USB: Universal Serial Bus, an industry standard for connecting peripheral devices, such as a digital camera, directly to a computer.
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TechXtra®
Published by the National Science & Technology Education Partnership (NSTEP)
formerly Electronics Industries Foundation
2500 Wilson Blvd.
Suite 210
Arlington, VA
22201-3834
(703) 907-7400
www.nationalstep.org
President
Barbara L. Wortmann
Director, Educational Initiatives
Marie Wiggins
Executive Editor, TechXtra
Debra D. Bass
Writer
Frank Klimko
Web Designer
Chris Korin
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NSTEP is grateful for the support provided for this issue by:
Olympus America Inc.
Editorial Advisory Committee
Jennifer Martino, PhD, science teacher, Governor Livingston High School
John E. Riley, Radiation Safety Consultant, Just-In-Time Industrial Hygiene
Gary Ybarra, PhD, Director of Undergraduate Studies, Duke University
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TechXtra, a free e-newsletter published periodically from September through May by the National Science & Technology Education Partnership (NSTEP), brings new technology to life for students and their science, technology and math teachers. And, it brings life to technology with a close-up look at the jobs, career paths and education of the people who make it all happen.
National Science & Technology Education Partnership (NSTEP) is a nonprofit 501(c )3 organization that is dedicated to developing tomorrow's technology leaders.
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