Definitions

Additive Color: The result of mixing the primary colors, (red, green and blue). Creating a visible spectrum of colors.

Aperture:  The opening formed by an iris diaphragm in the lens that controls the amount of light allowed to expose film or digital sensor.

Aspect Ratio: The ratio between the width and height of an image, film or image sensor.

Attachment:  A digital file that can be attached to an email and opened or saved on the recipient’s end.

Automatic Exposure: The mode of operation in a camera that automatically adjusts, shutter speed, aperture, or both, for proper exposure.

Automatic Flash: The normal default mode for most point and shoot cameras. This mode allows the camera to judge when the light is low enough to use the flash.

Backlit: The subject of the photograph is lit from behind causing the subject to be underexposed. Use fill flash to compensate.

Banding:  A visible streak through a photograph created by dirt or a malfunction of the printing device.

Bandwidth: The capacity of a network to transfer data. Associated with the ability to send files over the internet. The wider the bandwidth, the faster the transfer rate.

Bit: A binary digit. The smallest piece of binary information used by a computer.

Byte: A byte equals 8 bits

Camera-ready artwork: Flat or digital art that has been completely prepared for prepress or printing.

CCD: Charge-coupled device. A common image sensor found in digital cameras.

CMOS Chip: An image sensor found in digital cameras. This technology uses less power than CCD. It also has a lower manufacturing cost

CMYK: Cyan, magenta, yellow and black. A color mode used to assign inks to printing.

Color Balance: The standard of creating a print that matches the color of the original scene. Controlled by the type of film used, the type of filter used on the camera, the programming of the printer, and the correct chemical balancing of the processors.

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.

Color Gamut: The range of colors available in an output device or image.

Color Space: The number of colors that can be produced based on the ability of the out put device and the media that is used.

Compact Flash: A form of flash memory storage used in digital cameras.

Compression, loss less:  A file compression type that reduces size of the file without degrading the image.

Compression, lossy: A file compression type that reduces the size of the file, but, in the process, degrades the image. The image data cannot be restored to its original quality.

Contrast: The range between the darkest and brightest points of an image.

Decompression: Fully restoring a digital file to its original data content.

Dedicated Flash: A flash that is specifically designed to operate with a specific camera. When using a dedicated flash, the camera communicates with the flash to allow the user to use automatic exposure modes. (See TTL)

Depth of field: The distance from the furthest to the closest points in a photograph that are in focus. Depth of field is controlled by the size of the aperture being used. By adjusting shutter speed to compensate for a narrow aperture, depth of field can be increased. A larger opening in the lens will decrease depth of field.

Digital Color Printing:  Any number of printing devices that use digital data to create a hard copy. Ink jet, LED, laser, CRT are all methods used in photographic quality printing.

Docking Station: An accessory for digital cameras that connects to your computer to transfer images.

Dots per inch (DPI): A measurement of printer resolution that counts the number of dots placed by the printer in one inch. Measurements can be calculated horizontally or vertically.

Downloading: To transfer data from a large computer to a smaller computer or device.

Driver: A software program that communicates with the computer to allow a device to work properly.

Dye Sublimation: A color printing technology that uses thermal heads along with a transfer material to create an image on a receiver paper.

Exposure/Focus lock: The act of holding down the shutter button half way to lock onto a focus and exposure, and recomposing with out allowing the camera to change its settings to the new scene.

Exposure: The amount of light that reaches the film or digital sensor, controlled by the sensitivity of the film or sensor, and the aperture and shutter speed.

Fill Flash: Intentionally turning your flash on in order to fill shadows on a bright sunny day, or to override backlighting conditions when shooting indoors when the camera is unable to do so in automatic mode.

Fire wire: One of the fastest peripheral standards ever developed. Transfer rates of up to 800 mega bits per second.

Firewall: A security system that protects the computer from outside access.

Firmware: Software stored in the computers read only memory (ROM) and cannot be changed. Usually associated with the boot up process.

Flash card reader: A device that reads flash memory and transfers it to a computer.

Flash, Slave: A flash that fires when it senses a flash from another unit.

Flash: Used to emit a short burst of bright light to eliminate the need of slowing shutter speed to a point of creating a blurry picture. A flash uses xenon gas in a tube and is powered through a capacitor by a battery.

FlashPix: A file format created by Kodak that contains a number of resolutions that can be viewed independently.

Focal Length: The distance from optical center of a lens to the surface of the exposure plane. This is usually measured in millimeters. The longer the focal length is the more narrow the angle of view, the more objects are magnified. Normal focal length lens provides about the same angle of view, as the photographer would see it.

Focus: The process of making the image sharp on film or sensor. Most cameras have auto focus or fixed focus. Manual focus cameras are adjusted through the lens or by using a guide on the camera.

F-Stop: A measurement used as a benchmark to correctly expose film, rate a lens as to how “fast” it is and is controlled by an iris in the lens to make the opening larger or smaller.

FTP (File Transfer Protocol): Used to efficiently transfer files over a TCP/IP network.

GIF: An image format file that is used on the web for animations.

Gigabyte: A unit of memory in a computer that is equal to 1,024 megabytes.

Global color correction: A color correction to a print that affects the entire image equally.

Gray Market Merchandise: Merchandise that is imported out side normal manufacture’s distribution channels, at a low cost, due to rate of exchange. Then sold in the United States as discounted merchandise. Common gray market items are film and cameras.

Gray Scale: A series of 256 tones raging from pure white to pure black.

Guide Number: A rating of a flashes power. Good to use when shopping for flash and comparing different models.

Histogram: A graphic representation of the brightness and color in a scene based upon the frequency of occurrence of each value.

Hot Shoe: A clip usually on the top of a camera used to mount an external flash. Most hot shoes will allow the flash to communicate with the camera to create the proper exposure.

HTML: Hyper text markup language.

HTTP: Hyper text transfer protocol.

Image Sensor: See CCD and CMOS chip.

Interpolation: The process of adding extra pixels to an image by using nearby pixels to estimate the color and brightness for the pixels in a larger image. Some digital cameras will interpolate pixels to increase the range of the zoom lens.

ISO: The rating of how sensitive film or sensor is to light. The higher the number is, the more sensitive the film.

Jpeg: The most common image file using lossy compression to reduce file size. Developed by the Joint Photographic Experts Group.

Kilobyte: Digital data equal to 1,024 bits.

LCD:  Liquid crystal display. Used as viewing device on digital cameras.

LZW: A compression used to reduce the size of an image file. Usually associated with the .tiff format.

Macro Photography:  Using a mode or a special lens that allows very close up photography without making the photograph blurry.

Matrix Metering: An exposure system included with some cameras that breaks the scene up into a grid, then evaluates each section of the grid to produce the best possible exposure.

Mega pixel: The measurement of one million pixels. A four mega pixel camera has four million pixels in each image.

Megabyte: Digital data equal to 1,048,576 bytes.

Memory stick:  A flash memory chip developed by the Sony Corporation.

Metamerism: A phenomenon that occurs when two or more photographs visually match under certain lighting conditions, but not under all lighting conditions.

MPEG: A digital video format developed by the Motion Pictures Expert Group.

Multiple Exposure: A photograph made up of two or more images shot over each other.

Multisession: A CD-ROM format that allows information to be recorded incrementally in different sessions on the same CD.

Overexposure: When the film or sensor is exposed with too much light. By either having the aperture to large, the shutter speed to slow, or a combination of both.

Panoramic mode: A mode that allows the photographer take wide-angle photographs. As wide as 360° with a digital camera.

Parallax: An effect produced with a viewfinder camera shooting close up. The scene through the viewfinder is offset by the scene through the lens due to the distance between the two.

Pixel: The element of a digital image where color values and brightness have been recorded.

Pixelization: A visual effect seen when a digital image is enlarged beyond its capabilities, and pixels become evident.

Point and Shoot Camera: A compact automatic camera that will usually have the flash built in.

PPI: Pixels per inch. A measurement of the number of pixels in width and height for each inch of the photograph.

Prepress: The work done to a digital job before printing, laying out the text, graphics and sizing.

Preview Screen: A small LCD screen on the back of a digital camera that allows the user to compose, and view digital photographs.

Range Finder:  A camera with has a viewfinder separate from the lens.

Raw Format: The uninterpolated data collected by the image sensor before transforming it to a .jpg or. tiff.

Recycle time: The amount of time a digital camera takes to process and store a digital image to flash memory.

Red Eye Reduction Mode:  A mode on most modern automatic cameras that attempt in different ways to constrict the iris of the subject’s eyes, in order to reduce the red eye recorded on the film or image sensor.

Red Eye:  A problem that shows up when using a flash that is close to the lens. The light from the flash reflects off the blood in retina of the eye and records on the film as red eye. Common with light eyed people.

Removable Media:  Flash memory that can be removed from a digital camera.

Resolution: Usually measured in PPI. Determines the maximum document size, depending on use, based on the number of pixels in width and height.

RGB: The primary colors of red, green and blue. The combinations of these colors create the visible spectrum used in digital photography.

Shutter Speed:  The length of time the shutter stays open to allow light onto the film or image sensor.

Shutter: The device in a camera that opens and closes in a set amount of time to allow the film or image sensor to be exposed with light through the lens.

SLR: Single lens reflex camera. A camera with one lens that is used for viewing through and taking the picture.

Smart Media:  A form of flash memory storage used in digital cameras.

Spot Metering: An auto exposure mode that sets the exposure based on a small circle in the center of the viewfinder.

TIFF (Tagged Image File Format): An image format designed for scanned images.

TTL Metering: A Dedicated flash that will set the exposure of the camera in an automatic mode. (See dedicated flash)

TWAIN: Technology Without An Interesting Name. A program that allows graphics software to capture images from a scanner in a readable format.

Underexposure: Not allowing enough light in to the film or image sensor to render an image that is as the eye sees it. Will produce dark or grainy photographs.

Upload: To send a file through a network to another computer or device.

URL: Uniform Resource Locator. Web site address.

Vector Image: Images created by mathematical shapes, lines, and groups of objects rather than pixels.

White Balance: Setting the white point on a digital camera based on the lighting conditions that photographs will be shot under.

Wide Angle lens: A short focal length lens that allows a wider angle of view than a standard lens.

ZIP: An efficient way to compress files that are sent over the internet.

Zoom Lens:  A lens that allows the user to change the focal length of the lens within a preset range. Zoom lenses are available in a wide variety of ranges.