Bit Depth – number of bits used to define a pixel’s color. B&W image bit depth can range from 2 to 8; color images range from 8 to 24 (or more).  A 24-bit image is capable of having 16.7 million (2²⁴) color values.

Burst – Digital camera feature that allows several images to be taken in rapid succession. 

Compression – Algorithm used by a digital camera or computer software that reduces an image file size by removing data that is duplicated or has no value.  “Good/Better/Best” settings (or similar terms) found in a digital camera menu determine how much compression will be used. “Best” uses the least compression and is the most suitable for images that will be printed.

DPI – Dots Per Inch. The number of dots per linear inch defines the resolution of a printer, monitor, or other output device.  Most monitors display 72 dpi, while some printers can produce over 2000 dpi.  To print a photo quality image, 300 dpi is sufficient.

Digital Zoom – The process of cropping and enlarging an image by a digital camera.  Interpolated pixels are added, so the result is often a fuzzy or grainy image.  It’s best to use an optical zoom instead.

Digitize – Converting analog information, such as film, into digital form for computer use.

Download – Transferring image data from a digital camera to a computer or printer.

Image Sensor – Area of a digital camera that contains photosites (one for each pixel) that record the light as it enters the lens.  Most digital cameras use a CCD or CMOS image sensor.

Interpolation – Increasing the number of pixels in an image by duplicating adjacent pixels or filling in color information by averaging values of neighboring pixels.  If too much is used, image quality and sharpness will decrease significantly.

JPEG – Joint Photographic Experts Group.  This group created the popular file format, pronounced “jay-peg,” that is used to store digital images.  It uses lossy compression to reduce the file size so more data can be stored on a memory card, CD, or hard drive.

Lag Time – Delay between pressing the shutter button and when the digital camera captures the image.

LCD – Liquid Crystal Display.  This tiny monitor on a digital camera lets you see the image that is about to be taken, review images saved on the memory card, and change the camera settings.

Megabyte – MB; equivalent to 1,048,576 bytes of digital or computer memory.

Megapixel – MP; one million pixels

Memory Card – Small storage device used to save image and movie files.  They are reusable, durable and come in many different sizes and capacities.  Some common types used in digital cameras are CompactFlash, SmartMedia, and Memory Stick^®.   Secure Digital cards are increasing in popularity because they are so tiny (about the size of a dime) and come in 1GB (GB = 1000 MB) capacities.

Noise – Loss of detail caused when pixels on the image sensor misread the incoming light.

Optical Zoom – Motorized elements in a camera lens that adjust to bring an object closer or farther away.  Most digital cameras have at least a 2x or 3x optical zoom (some models go up to 10x).  Be sure to check the camera specifications for the “35mm equivalent” to ensure that it covers the range that you expect.

PPI – Pixels Per Inch.  The number of pixels per inch obtained from a scanned image.

Pixel – Picture Element.  These small squares are the building blocks of a digital image and are the equivalent to grain on a film negative.  Each pixel is assigned a color (see bit depth) by a digital camera or scanner.  A high quality image is formed when hundreds of thousands or millions of pixels are seen together without the appearance of individual squares.  You may be interested to know that film has 20 million (or more) pixels and the human eye can see the equivalent of about 120 million pixels.

Photo Kiosk – Machine, such as a Kodak Picture Maker, that allows the consumer to print digital images from a picture or digital media.

RGB – Red, Green, Blue.  The colors to which digital cameras and the human eye are sensitive.

Recycle Time – Time it takes for the camera to process and store the image.

Resolution – The quality of a digital image depends on the pixel density, or resolution, which is expressed in DPI or PPI.  It is determined by multiplying the number of horizontal pixels by the number of vertical pixels.  Larger numbers indicate better image quality.

White Balance – Digital camera setting that automatically corrects colors in the image to match the source of light.  Without white balance, a shady or overcast day will have a blue cast, incandescent light bulbs will have an orange or yellow cast, and fluorescent light bulbs will have green or blue cast.