For millennia, text and pictures were more or less equals: Scribes illuminated or illustrated a manuscript at the same time the text was drawn. The only technology involved was, say, a quill pen and the tools used to sharpen it. When both text and graphics were hand-drawn, it took a little longer to create an illustration, but, as they say, a sketch is worth a thousand words. Until the invention of movable type, text and graphics merged seamlessly, with neither form of visual communication having a "technological" advantage over the other. Of course, manual methods sharply limited access to visual information, unless you were royalty, rich, or worked in a profession that required literacy.
That balance between text and graphics changed dramatically when movable type simplified the printing of books about 500 years ago. The distribution of text suddenly became several orders of magnitude easier than the reproduction of images. Movable type let text reach the masses, but pictures still had to be laboriously carved as woodcuts, engraved in steel, or converted to halftone dots before they could be printed. The transmission of words by telegraph predated wirephotos and fax machines by roughly a century, and the first 35 years of the Computer Age were dominated by text and numbers. Newspaper advertisements in the 1860s were better illustrated than accounts of the Civil War, and computer artists a century later sometimes created portraits by assembling ASCII characters into crude mosaics (if you've seen some of the pinups that resulted, you'll know why they were considered crude).
It's only been in the past few years that digital imaging has provided the technology we need to meld text and pictures seamlessly with our documents, computer presentations, web pages, and other electronic media.
The advantages of digital imaging are simple: If you have a digital camera, computer, and printer, you can capture images, refine or retouch them, and distribute them though printouts, e-mail, or web pages. You can accomplish all these things in the span of a few minutes or hours without relying on film manufacturers, photofinishers, professional retouchers, or, in most cases, the postal system.
The disadvantages are vanishing. Digital cameras still cost more than film cameras of equivalent features and quality, but the cost "penalty" is becoming smaller and smaller. Today, you can pay a few hundred dollars for a good film camera, or buy a digital camera with the same quality but greater convenience for perhaps 20 to 50 percent more. Digital "film," while almost infinitely reusable, costs more than film, but memory cards can be purchased today for $20-50 that will hold hundreds of images. Computer-generated prints you make at home are still more costly than the drugstore kind, but today your drugstore will be happy to make those prints for you for about the same price as making prints from film.
As recently as two centuries ago, unless you had met a relative personally or came from a family wealthy enough to have commissioned a portrait, you probably didn't even know what your ancestors looked like. Your own grandfather might have been a stranger to you unless you had met him personally. Today, you can snap a picture of the old geezer with your digital camera and e-mail it to a long-lost relative who might never be able to drop by for a visit. The average computer owner today can do useful things with images that were beyond the imagination of the wealthiest royalty in the past.
Even though we're currently immersed in a transition from conventional film photography to digital photography, the two technologies actually have very little in common, except on an abstract level. Digital photography didn't evolve from film imaging any more than audio CDs evolved from phonograph records or magnetic tape cassettes. While the technologies serve the same needs, their origins are very different. Traditional photography has its roots in chemical technology, which gave us photosensitive films, plates, and papers. Digital imaging comes from a foundation of electronics (even though digital sensors are created chemically). The chief technological convergence between the two lies in the optical and exposure systems of cameras: Both film and digital cameras use lenses, viewfinders, and lens apertures.
We can skip the history of conventional photography entirely, and jump ahead roughly 100 years to 1951, when Bing Crosby Laboratories (yes, that Bing Crosby) developed the first videotape recorder to convert live TV images to a format that could be stored onto magnetic tape. A few years later, Ampex marketed the first commercial VTR for a whopping $50,000. Although TV cameras had been available previously, the ability to save those images permanently really marks the beginnings of digital photography. Video cameras and digital cameras generally use a sensor called a CCD (charged coupled device), developed in 1970 (although other types of sensors will be important in the future). The early VTRs are truly the granddaddies of our present day digital cameras.
True digital photography came later in stages, nudged along by your tax dollars at work. In the 1960s, NASA converted from analog to digital signals for the lunar missions that mapped the surface of the moon, because, as you probably know, analog signals can fade in and out, whereas digital information can be captured virtually error-free. The first heavy-duty image processing was developed in this era, as NASA put the power of computer technology to work, enhancing the images returned by its various space probes. The Cold War, replete with spy satellites and various super-secret imaging systems, also helped push the development of digital photography.
The first film-free electronic camera was patented by Texas Instruments in 1972. One of the patent drawings for this system is shown in Figure 1.3. The chief drawback of this system was that, had it ever been produced, it would have required viewing the still photos on a television. TV viewing was also an option for the later Sony Mavica, introduced in August, 1981 as the first commercial electronic camera. However, the Mavica could also be attached to a color printer. Yet, even the Mavica wasn't a true digital camera; it was more of a video camera that was able to capture and display individual frames.
Figure 1.3. The first filmless electronic camera was patented by Texas Instruments more than 30 years ago.
The Mavica (for Magnetic Video Camera) recorded up to 50 images on two-inch floppy disks with a 570 x 490-pixel CCD sensor rated at the equivalent of ISO 200. It had a single shutter speed of 1/60th of a second, a manual aperture setting, and three interchangeable lenses in 25mm wide-angle, 50mm normal, and 16-65mm zoom focal lengths. The system might seem primitive today, but keep in mind that the original Mavica was developed a quarter century ago!
The emergence of electronic photography in the 1980s was particularly exciting for me. I was doing work for Eastman Kodak Company (an early leader in digital photographic technology) as a technical writer and helped introduce products like the first megapixel sensor, the Kodak Photo CD system, and the Kodak DCS-100. Based on a Nikon F3 body and priced at $30,000, this was one of the first digital cameras I ever used. (Thanks to a Kodak loan; I certainly couldn't have afforded to buy one!) This pioneering system had a 1.3 megapixel sensor (about the same resolution as many $100 digital cameras today), and stored its images on an external 200MB hard drive. The total kit weighed 55 pounds, so only well-muscled and well-heeled photographers who needed to make prints no larger than 5 x 7 images could justify one of these babies.
The whole decade of the 1990s was a tantalizing one, as vendors with their roots in conventional photography (such as Kodak and Fuji) vied with more electronics-oriented firms like Apple, Casio, and Sony to produce digital cameras that, at $500 to $1,000, were actually affordable. Unfortunately, early models like the Apple QuikTake 100 (1994), the Casio QV-11 (introduced late in 1995 with an LCD monitor), and my own first Epson PhotoPC 600 (1997), were handicapped by what we today would consider to be extremely low resolution, ranging from 320 x 240 to 1024 x 768 pixels. Digital cameras of that era had just enough muscle to make them attractive, but not enough to make them useful, except for illustrating web pages or (in my case) for quick snapshots published as two-inch wide illustrations in books and magazines.
Digital photography really didn't start to take off until the new millennium, when sensors with two megapixels or more of resolution, built-in zoom lenses, and inexpensive removable storage devices like CompactFlash began making digital cameras the functional equivalent of their film counterparts (in many ways) at prices that anyone who really needed digital imaging could afford.
The availability of $100-$200 inkjet printers that could produce inexpensive photo-quality prints didn't hurt either. Digital photographers might work with their images on-screen, but they still want to be able to create prints to pass around, send to relatives who don't have electronic mail, or paste into albums. In some respects, photo printers were the last piece of the puzzle needed to make digital photography popular to the masses.
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