Digital Cameras
The History of Digital Technology
Digital cameras differ from traditional cameras by using solid state image sensors to converted light to digital pictures rather than capturing the image on film. Digital imaging for other purposes had been around for a longer period.
The history of digital technology began earlier. As with many inventions that have become public domain, NASA began dabbling with digital imaging technology as far back as the 1960s, using it to convert signals from analog to digital. The signals were acquired with space probes and the signals, converted to images, mapped the moon's surface.
Other sectors of the government soon saw the opportunities presented by this emerging digital technology and began a similar program involving spy satellites. Today of course similar applications are available for free to anyone with internet access for example Google's satellite maps that show you the whole world and even the moon.
Digital Cameras Begin to Emerge
The true digital cameras did not simply emerge as a new consumer product. There were several other products that led to its creation by stepping into the film-less arena.
Digital cameras as we know them today first became available for consumers around the mid 1970s. At that time, Kodak developed a number of solid state image sensors which converted available light into digital images. The target markets for the new Kodak digital cameras were both professional and hobbyist.
Then in 1986, Kodak once again took the digital world to a new level when they developed the original megapixel sensing unit, with the ability of capturing 1.4 million pixels. Finally, a 5x7-inch digital high quality print was available to consumers.
Now that the ball was rolling, the camera industry began to gather speed and introduced the ability to connect to the home computer to download pictures, docking units to both link with the computer and charge the batteries, software to manipulate and edit pictures, and special printers dedicated to digital photography. This is a snapshot of the history of digital cameras until today.
How Digital Cameras Work
In the digital world, data, or information, is represented by strings of 1's and 0's. In this case these digits translate to the individual pixels or basic units that combine to make up the image you see. When the capture button on the camera is pressed, a charge coupled device (also known as a CCD) creates an electron equivalent of the captured light which in turn ends up converting the pixel value into a digital value.
Each picture is stored in the camera's memory until it is downloaded to its destination, usually a computer or a CD. Typically, the form of camera memory is a memory card which can be replaced. Indeed, this is one of the great advantages over traditional cameras – no film to buy.
What Features to Look for in a Digital Camera
Resolution is one of the biggest considerations and in many cases is one of the top features that drives a camera's price. Resolution is a measure of detail that a specific camera will capture. The basic unit of measurement when referring to digital camera resolution is the pixel. The higher the number of pixels the better because a higher level of detail is captured. This becomes important when blowing up pictures to larger sizes.
Digital cameras are rated in megapixels (millions of pixels). A 1.0 megapixel camera is considered to be something of a toy while a 5.0 megapixel camera is commonly found being used in professional digital photography when creating studio grade portraits or taking pictures for a wedding.
The lens is important and translates directly into what you intend to use the digital camera for. A lens that has a fixed focus and fixed zoom is bare bones and just for simple snapshots. Zoom lenses come in two flavors: the optical zoom lens and the digital zoom lens. The optical zoom is preferable because it zooms by changing the actual focal length of the lens whereas the digital zoom uses an interpolation algorithm to zoom; it “infers” information by evaluating neighbor information. This results in a grainy photo.
Replaceable lenses are found on many higher end cameras. The good thing about them is that they increase the camera's versatility. Kinds of lenses to be found are zoom lenses, close-up lenses, color lenses for effects, and panoramic lenses.
How many useful digital camera accessories are available for a particular model? As mentioned above, some cameras, like Kodak, offer a docking system which not only is the interface to the computer but also doubles as a battery charger when the camera is not in use, ensuring the it starts off with a full charge when needed.
Choosing a digital camera is not easy, but if you have decided on a particular model you will enjoy taking digital pictures wherever you go to: on vacation, at a family dinner, at a party with friends, at school, etc.