Digital Camera/Photography Terms

Digital Zoom

A method of zooming on a digital camera either by increasing the size of the pixels or by interpolating between them. The image doesn't physically get any closer and no extra information is collected, as the optics on the camera stay in place. The process is similar to cropping meaning the resolution or megapixel rating of the photograph is reduced. Digital zoom is not recommended if the picture is destined to be printed out.

Automatic Exposure

A mode of camera operation in which the camera automatically adjusts the aperture, shutter speed, or both for proper exposure.

Red Eye Reduction Mode

A mode that fires a preliminary flash to close the iris of the eye before firing the main flash to take the picture.

ISO

A number rating indicating the relative sensitivity to light on an image sensor or photographic film. Higher ISO's (400, 800, 1600) are more sensitive to light and require less exposure than lower ISO's (100,200)

F-Stop

A numerical designation (i.e. f/2, f/4, f/22)) indicating the size of the aperture. (lens opening)

Panorama

A photograph with much wider horizontal coverage (up to 360 degrees and more) than a standard photograph.

TIFF

A popular image format used in digital photography that is not condensed. Time Lapse Photography − Taking a series of pictures at present intervals to show such things as flower blossoms opening.

Interpolated Resolution

A process that enlarges an image by adding extra pixels without actually capturing light from those pixels in the initial exposure.

Flash Memory

A card containing chips that store images.

Flash Memory Card

A card containing chips that store images.

Hot Shoe

A chip on the top of the camera that attaches a flash unit and provides an electrical link to synchronize the flash with the camera shutter.

Image Editor

A computer program that enables you to adjust a photo to improve its appearance.

Panoramic Mode

A digital camera mode that uses just the center band on the image sensor to capture an image that is much wider than it is tall.

Attachment

A file such as a photograph sent along with an email so it can be viewed or saved at the recipients end.

Slave Flash

A flash that fires when it sense the light from another flash unit.

Fill Flash

A flash used to fill shadows even when there is enough light to otherwise take the photograph.

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 a photo.

USB Port

A high-speed port that allows you connect one electronic device to another.

Macro Mode

A lens mode that allows you to get very close to objects so they appear greatly enlarged in the picture.

Zoom Lens

A lens that let's you change focal lengths on the fly.

Long Focal Length (Telephoto) Lens

A lens that provides a narrow angle of view of a scene. These lenses include less of a scene than a lens of standard focal length therefore magnifying objects in the image.

Short Focal Length (Wide Angle) Lens

A lens that provides a wide angle of view of a scene, including more of the subject area than that of a lens with normal focal length.

Normal Focal Length Lens

A lens that provides about the same angle of view of a scene as the human eye and does not seem to magnify or diminish the size of objects in the image.

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.

Memory Stick

A memory card slightly smaller than a stick of gum that utilizes flash based storage.

Orientation Sensor

A sensor that knows when you turn the camera to take a vertical shot and rotates the picture automatically so it isn't displayed on its side when you view it.

Viewfinder

A separate window on the camera through which you look to compose the image.

Gray Scale

A series of 256 tones ranging from pure white to pure black.

Preview Screen

A small LCD display screen on the back of the camera that can be used to compose or view the photograph.

Photo Site

A small area on the surface of an image sensor that captures the brightness for a single pixel in the image. There is one photo site for every pixel in the image.

Aperture

A small circular opening inside the lens that can change in diameter to control the amount of light reaching the cameras sensor as a picture is taken. The aperture diameter is expressed in f-stops: the lower the number the larger the aperture. For instance, when the aperture is set to f/2.8 it is larger than when it is set to 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, generally excluding point and shoot, have an aperture priority mode that allows you to adjust the aperture to your own liking.

Image Sensor

A solid-state device containing a photo site for each pixel in the image. Each photo site records the brightness of the light that strikes it during an exposure.

Ring Flash

A special circular flash that fits around the rim of a lens to take close-up photos.

Single Lens Reflex (SLR)

A type of camera with a lens that is used for both viewing and taking the picture. By looking through the viewfinder you are looking though the lens and can visualize the image in and out of focus.

JPEG

A very popular digital camera file format that uses compression to reduce file size.

Smart Media

A wafer thin matchbook size memory card.

Highlights

The brightest parts of a photo.

Stopping Down

To decrease the size of the lens aperture. (to go from f/2 to f/5.6) Stopping down is the opposite of opening up.

Opening Up

To increase the size of the aperture. (to go from an f/5.6 to f.2) Opening up is the opposite of stopping down

Optical Resolution

The true resolution of an image based on the number of photo sites on the surface of the image sensor.

Burst Mode

A cameras ability to take one picture after another as long as you hold down the shutter release button.

Rangefinder

A camera design that has a viewfinder separate from the lens. When you view a scene through a rangefinder you are not looking directly through the cameras attached lens.

TTL (Through the Lens)

A camera design that let's you compose an image while looking at a scene through the lens that will take the picture.

Flash Card Reader

An accessory that attaches to your computer by cable, which allows you to insert a flash memory card in order to transfer files to your computer.

Stop

An aperture setting that indicates the size of the lens opening. (f/22 is the smallest opening, while f/1.8 is the largest) Changing the aperture from one setting to the next doubles of halves the amount of light reaching the image sensor. Changing the shutter speed from one setting to the next does the same thing. Either changes the exposure one stop.

Shutter Priority Mode

An automatic exposure system in which you set the shutter speed and the camera selects the aperture (f-stop) for correct exposure.

White Balance

An automatic or manual control that adjusts the brightest part of the scene so it looks white.

Pixelization

An effect seen when you enlarge a digital image too much making the pixels more noticeable.

Red Eye

An effect that causes people eyes to appear red in flash exposures.

Port

An electrical connection on the computer into which a cable can be plugged so the computer can communicate with another device such as a camera, card reader, printer, or modem.

Automatic Flash

An electronic flash unit with a light sensitive cell that determines the length of flash for proper exposure by measuring the light reflected back from the subject.

Matrix Metering

An exposure system that breaks the scene up into a grid and evaluates each section to determine the exposure.

Gif

An image file format designed for display of line art on the web

Megapixel

An image or image sensor with at least one million pixels.

Resolution

An indication of the sharpness of an image on a printout or display screen. It is based on the number and density of the pixels used. The more pixels used in an image, the more detail can be seen and the higher the image's resolution.

Scanner

An input device that uses light to read printed information including text, graphics, and bar codes, and transfers it to the computer in a digital format.

Spot Metering

Automatic exposure based on a meter reading of a small circle in the center of the viewfinder.

Angle of View

How much of the scene can be included in the picture.

Saturation

How rich the colors are in the photos.

Underexposure

Exposing the image sensor to less light than is needed to render the scene as the eye sees it. Underexposure results in a photograph that is too dark.

Overexposure

Exposing the image sensor to more light than is needed to render the scene as the eye see it. The result is a blown out photograph that appears too light.

Bitmap

Images formed from pixels with each pixel a shade of gray or color. Using 24-bit color, each pixel can be set to any one of 16 million colors.

LiOn

Lithium Ion rechargeable battery.

Buffer

Memory in the camera that stores digital photos before they are written to the memory card

NiCad

Nickel cadmium battery.

NiMH

Nickel metal hydride battery. Ecologically safe and very efficient.

Complementary Metal-Oxide Semiconductor (CMOS)

One of the two main types of image sensors used in digital cameras. Its basic function is the same as that of a CCD. CMOS sensors are currently only found in a handful of digital cameras.

Charge Coupled Device (CCD)

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 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.

Optical Zoom

Optical zoom utilizes a lens that physically extends to magnify your subject. A motor controls the lens movement. When you press the "W" (wide) the image is reduced and when you press the "T" (telephoto) the image is magnified.

Noise

Pixels on the image sensor that misread the light.

Upload

Sending a file from your computer to another device.

Removable Media

Storage media that can be removed from the camera. The content of this media can be deleted and re-used countless times.

Time Lapse Photography

Taking a series of pictures at present intervals to show such things as flower blossoms opening.

Archival

The ability of a material, including some printing papers and compact disks, to last for many years.

Exposure/Focus Lock

The ability to point at one part of the scene and hold the shutter button halfway down to lock in exposure and focus settings when you point the camera elsewhere to compose the scene.

URL (Uniform Resource Locator)

The address of a Web Site.

Exposure

The amount of light that reaches the image sensor, which is controlled by the combination of aperture and shutter speed.

Refresh Rate

The time is takes the camera to capture the image after you press the shutter release.

RGB

The color system used in most digital cameras where red, green, and blue light is captured separately and then combined to create a full color image.

Shutter

The device in the camera that open and closes for a certain period of time to let light from the scene strike the image sensor.

Contrast

The difference between the darkest and lightest areas in a photo. The greater the difference, the higher the contrast.

Depth of Field

The distance between the nearest and farthest points that appear in acceptably sharp focus in a photograph. Depth of field varies with lens, aperture, focal length, and camera to subject distance.

Focal Length

The distance from the optical center of the lens to the image sensor when the lens is focused on infinity. The focal length is usually expressed in millimeters (mm) and determines the angle of view and the size of the object in the image. The longer the focal length, the narrower the angle of view and the more the objects are magnified.

CMYK (Cyan, Magenta, Yellow, Black)

The four colors in the ink sets 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.

Shutter Speed .

The length of time the shutter is open and light strikes the image sensor

Ambient Light

The natural light in a scene

Color depth

The number of bits assigned to each pixel in the image and the number of colors that can be created from those bits. True color uses 24 bits per pixel to render 16 million colors.

Focus

The process of bringing one plane of the scene into sharp clarity on the image sensor.

Download

The process of moving computer data from one location to another.

Compression

The process of reducing the size of a file.

Operating System

The program that controls the camera or computer's hardware. (Windows XP, Mac O.S. X)

Aspect Ratio

The ratio between the width and height of an image or image sensor.

Pixels (Picture Elements)

The small picture elements that make up a digital photograph.

Color Balance

the overall accuracy with which the colors in the photograph match or are capable of matching those int he original scene

Recycle Time

the time is takes to process and store a captured image.

Compact Flash

− A common type of digital camera memory card, about the size of a matchbook. There are two types of these cards, Type I and Type II. They vary only in their thickness, with Type I being slightly thinner. A Compact Flash memory card can contain either flash memory or a miniature hard drive. The flash memory type is more prevalent.