Digital Camera Basics
The Digital Photography workshop is aimed at beginners who want to apply digital photography skills to classroom situations. The Digital Photography in the Classroom section provides an overview of some possible classroom applications. Once you decide how photography might be applied to your teaching situation, you can focus on the skills needed to accomplish what you want to do. The kinds of photographs you want to take also will help determine what kind of camera is best suited to the task. Keep your camera manual handy!
The beauty of digital photography is that digital cameras provide immediate feedback. There is no film processing involved -- no darkroom, no toxic chemicals. Digital camera electronics can automatically balance light and color qualities, and focus. This makes it easier for amateurs to be successful without an extensive technical background in photography. Because of the instant feedback, it allows beginners to improve their skills, knowledge, and creativity. The quick feedback lets one fix mistakes on the spot and learn to apply the technology involved with photography.
Is your camera up to the task? Are you looking for a camera that will be able to do what you have in mind?
What to look for:
How it works -- in a nutshell...
A digital camera contains an imaging surface comprised of row (s) of tiny sensors that capture light and color information (CCD - sensor array). The information is converted into digital data that make up the photograph. The digital data is referred to as pixels (picture elements).
Resolution -- More pixels means more information -- higher is better. Higher resolution allows you to print larger photos without losing quality. If the image captured has a resolution of 640 x 480 that means that there are 640 horizontal pixels by 480 vertical pixels. If you multiply you get 307,200 pixels. This places the digital camera in the MegaPixel range (Mega means million). The more tiny sensors that can be placed on the camera's imaging surface, the better the resolution and picture detail will be. For more information about resolution, click here.
Optical or digital resolution? This is sometimes confusing. What kind of resolution is it? Optical refers to the actual number of sensors in the array. Digital resolution is interpolated resolution. Interpolated resolution results when software inserts more pixels. Optical resolution is the more important number to pay attention to. Again, this depends on what you want to do with the camera.
Lenses --camera focusing, the amount of light passing through the lens, and exposure are other issues affecting photo quality. Because the lens acts as a gateway into the camera, it needs to be made with a certain amount of precision in order to capture fine detail. Look for manufacturers of digital cameras that have been in the camera business for a while and have established reputations with optical capabilities.
Viewfinders -- Digital cameras usually come with an optical viewfinder and a small LCD monitor. LCD by it self has some disadvantages. It is hard to see when outside in sunlight. Also, framing your shot sometimes requires you to hold the camera out away from your body, making it more difficult to hold the camera still. Some cameras have a "steady shot" feature, which may be worth considering.
Zoom -- Simply put, 2x, 4x, 10x, 14x, etc. refers to the degree of image magnification-- the higher the number, the farther away you can be from the subject and still zoom in for a decent shot. There are two kinds of zoom lenses -- digital and optical. With optical zoom, the resolution stays the same regardless of how far you zoom in. However, with digital zoom, usually only the pixels in the center part of the sensor array are utilized. Consequently, the overall resolution can suffer to some degree.
Auto focus -- most digital cameras automatically focus on the subject -- usually on what ever object is in a particular area of the viewfinder. Many camera's have a manual override feature. Close-up photography is called macro photography. The camera may have an automatic setting for close up shots (usually a tulip symbol).
Memory and Storage -- Most digital cameras have removable storage cards such as CompactFlash, Memory Stick, Secure Digital (SD), xD, SmartMedia. A Multi-Card reader can be hooked up to your computer (via the USB port) thus enabling you to transfer/download the images. Some cameras also use a floppy disk or a CD (Sony Mavica series). The storage cards come in different size capacities. Digital cameras may also be connected directly to your computer with a cable (USB, serial, etc.).
Batteries and Power -- digital cameras need power for the LCD screen, the flash, etc. The may use Lithium ion batteries, rechargeable batteries, NiMH batteries, battery packs. Be prepared to use batteries!