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Glossary

Ambient light – The natural light in a scene.

Aperture - A small, circular opening inside the lens that can change in diameter to control the amount of light reaching the camera's sensor as a picture is taken. The aperture diameter is expressed in f-stops; the lower the number, the larger the aperture. For instance, the aperture opening when set to f/2.8 is larger than at f/8. The aperture and shutter speed together control the total amount of light reaching the sensor. A larger aperture passes more light through to the sensor. Many cameras have an aperture priority mode that allows you to adjust the aperture to your own liking. See also shutter speed.

CCD – Charge Coupled Device: one of the two main types of image sensors used in digital cameras. When a picture is taken, the CCD is struck by light coming through the camera's lens. Each of the thousands or millions of tiny pixels that make up the CCD convert this light into electrons. The number of electrons, usually described as the pixel's accumulated charge, is measured, then converted to a digital value. This last step occurs outside the CCD, in a camera component called an analog-to-digital converter.

CMYK – Cyan, Magenta, Yellow, Black. The four colors in the inksets of many photo-quality printers. Some printers use six ink colors to achieve smoother, more photographic prints. The two additional colors are often lighter shades of cyan and magenta.

Depth of Field - This is the area around the focal point where the photograph is still in focus. The larger the depth of field the more area around the central focal point will be sharp or "in focus". The depth of field is adjusted by the camera's aperture setting.

Digital camera – A camera that captures the photo not on film, but in an electronic imaging sensor that takes the place of film.

Downloading – The process of transfering photos from a camera memory card to the computer.

DPI – Dots per inch: A measurement of the resolution of a digital photo or digital device, including digital cameras and printers. The higher the number, the greater the resolution.

Exposure - The amount of light that is received by the recording material. The photograph's exposure is determined by the camera's aperture and shutter speed settings.

External flash – A supplementary flash unit that connects to the camera with a cable, or is triggered by the light from the camera's internal flash. Many fun and creative effects can be created with external flash.

Fill flash – A flash technique used to brighten deep shadow areas, typically outdoors on sunny days. Some digital cameras include a fill flash mode that forces the flash to fire, even in bright light.

FireWire – A type of cabling technology for transferring data to and from digital devices at high speed. Some professional digital cameras and memory card readers connect to the computer over FireWire. FireWire card readers are typically faster than those that connect via USB.

Focal length - How far away from the camera that the camera can have its point of focus.

Focus - How clear items are in the picture or photo. Many cameras come with an autofocus feature where the camera finds the focal point for you usually putting an indicator on the view finder. Often you can turn off the autofocus and use a manual focus where you turn the focus ring on the lens until you reach the desired focal point.

Grayscale – A photo made up of varying tones of black and white. Grayscale is synonymous with black and white.

Histogram – A graphic representation of the range of tones from dark to light in a photo. Some digital cameras include a histogram feature that enables a precise check on the exposure of the photo.
Image browser – An application that enables you to view digital photos. Some browsers also allow you to rename files, convert photos from one file format to another, add text descriptions, and more.

Image resolution - The number of pixels in a digital photo is commonly referred to as its image resolution.

Inkjet – A printer that places ink on the paper by spraying droplets through tiny nozzles.

ISO speed – A rating of a film's sensitivity to light. Though digital cameras don't use film, they have adopted the same rating system for describing the sensitivity of the camera's imaging sensor. Digital cameras often include a control for adjusting the ISO speed; some will adjust it automatically depending on the lighting conditions, adjusting it upwards as the available light dims.
(you’ve probably seen them on films - 100, 200, 400, 800 etc).
The lower the number the lower the sensitivity and the finer the grain in the shots you’re taking, producing more detail.

JPEG – A standard for compressing image data developed by the Joint Photographic Experts Group, hence the name JPEG. Strictly speaking, JPEG is not a file format; it's a compression method that is used within a file format, such as the EXIF-JPEG format common to digital cameras. It is referred to as a lossy format, which means some quality is lost in achieving JPEG's high compression rates. Usually, if a high-quality, low-compression JPEG setting is chosen on a digital camera, the loss of quality is not detectable to the eye.

Lag Time - The time it takes between when you push the button to take a photo and when the camera actually takes the photo. A long lag time can be a big drawback to a camera.

LCD - This the screen usually on the back of the camera that allows you to view the photos you have taken. The bigger the LCD the better idea you can get of how your photo came out.

Megapixel – Equal to one million pixels.

Panning – A photography technique in which the camera follows a moving subject. Done correctly, the subject is sharp and clear, while the background is blurred, giving a sense of motion to the photo.

Pixel – Picture Element: digital photographs are comprised of thousands or millions of them; they are the building blocks of a digital photo.

RAW – The RAW image format is the data as it comes directly off the CCD, with no in-camera processing is performed.

Red-eye – The red glow from a subject's eyes caused by light from a flash reflecting off the blood vessels behind the retina in the eye. The effect is most common when light levels are low, outdoor at night, or indoor in a dimly-lit room.

Resolution - This is term used for digital photos. The resolution refers to how many pixels a photo contains. The more pixels the higher the resolution. The higher the resolution, the better quality of the photograph, but also the more storage it will take up.

RGB – Red, Green, and Blue: the three colors to which the human visual system, digital cameras and many other devices are sensitive.

Saturation – How rich the colors are in a photo.

Sensitivity – See ISO speed.

Sensor - The recording medium for digital cameras. The sensors are made up of pixels. The more pixels the higher resolution of photo the camera can take.

Sharpness – The clarity of detail in a photo.

Shutter speed – The camera's shutter speed is a measurement of how long its shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. When the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for exactly 1/125th of one second. The shutter speed and aperture together control the total amount of light reaching the sensor. Some digital cameras have a shutter priority mode that allows you to set the shutter speed to your liking. See also aperture.

Storage card - A digital camera term referring to the memory card where the digital photos are stored. There are several standard types of memory storage cards including Compact Flash, Memory Stick, Smart Media, and xD.

Time Lapse - Some cameras allow you to program the camera to take a certain number of photos with a programmed time interval between photographs. Time lapse photography is often used to record something happening over a long period of time like a storm forming.

USB – Universal Serial Bus: a protocol for transferring data to and from digital devices. Many digital cameras and memory card readers connect to the USB port on a computer. USB card readers are typically faster than cameras or readers that connect to the serial port, but slower than those that connect via FireWire.

White balance – A function on the camera to compensate for different colors of light being emitted by different light sources.