A Short Glossary of Digital Photography Terms-PART-3

Jaggies - Slang term for the stair-stepped appearance of a curved or angled line in digital imaging. The smaller the pixels, and the greater their number the less apparent the "jaggies". Also known as pixelization. JFIF - A specific type of the JPG file format. Also known as EXIF JPEG - Joint Photographic Experts Group - The name of the committee that designed the standard image compression algorithm. JPEG is designed for compressing either full-color or grey-scale digital images of "natural", real-world scenes. It does not work so well on non-realistic images, such as cartoons or line drawings. JPEG does not handle compression of black-and-white (1 bit-per-pixel) images or moving pictures. See "JPG" below.
JPEG2000 - The new JPEG compression standard that will be used in digital cameras and software starting in 2002 (maybe?). It will feature higher compression but with less image quality loss.
JPG - The most common type of compressed image file format used in digicams. It is a "lossy" type of storage because even in its highest quality mode there is compression used to minimize its size.
Landscape mode. Holding the camera in its normal orientation to hake a horizontally oriented photograph.
LCD - Liquid Crystal Display. Two types: (1) a TFT high-resolution color display device like a tiny TV set. (2) A monochrome (B&W) information display using black alphanumeric characters on a gray/green background.
LED - Light Emitting Diode. All those wonderful little red, green and yellow indicator lights used on cameras, power supplies and most electronic devices.
Li-ion - Some digicams are packaged with a lithium-ion rechargeable battery pack. Lithium batteries are lighter but more costly than NiMH or NiCd type of rechargeable cells. Lithium cells can be recharged regardless of their state of discharge, they're lighter in weight and maintain a charge better in colder temperatures. Li-ion also holds a charge longer when idle. Lossless - Storing the image in a non-compressed format, see TIFF.
Low Pass Filter - Most digital SLR cameras employ a Low Pass Filter (LPF) or Anti-Aliasing (AA) filter in front of the imager to help eliminate color aliasing (moire) problems.
Long-focal-length lens (telephoto lens). A lens that provides a narrow angle of view of a scene, including less of a scene than a lens of normal focal length and therefore magnifying objects in the image.
LZW. -A compression scheme used to reduce the size of image files.
Macro mode.- A lens mode that allows you to get very close to objects so they appear greatly enlarged in the picture.
mAh - A rating used in the consumption of power of an electronic device such as an LCD or the storage capability of a device like an NiMH or Nicad rechargeable battery (i.e. 1600mAh cell). It stands for milliAmperehour.
Matrix Metering. -An exposure system that breaks the scene up into a grid and evaluates each section to determine the exposure.
Megapixel - CCD resolution of one million pixels. Digicams are commonly rated by Megapixels. You multiply the horizontal resolution by the vertical resolution to get the total pixel count:
1280 x 960 pixels = 1 Megapixel1600 x 1200 pixels = 2 Megapixels2048 x 1536 pixels = 3 Megapixels2272 x 1704 pixels = 4 Megapixels2560 x 1920 pixels = 5 Megapixels ... and so on
Memory stick. -A flash memory storage device developed by Sony.
Memory Stick Pro - The year 2003 upgrade to Sony's Memory Stick flash cards. The new MS Pro cards are available in 256MB, 512MB and 1GB capacities and offer faster read/write times. All of Sony's digicams made in 2003 or after can use MS Pro cards.
Microdrive - IBM/Hitachi miniature hard disk drive for digital cameras and PDA devices. Packaged in a CompactFlash Type II housing and available in 170MB, 340MB, 512MB, 1GB, 2GB, 4GB capacities.
miniCD - The small diameter (3-inch) CD discs. miniCD-R and miniCD-R/W discs are used in the Sony Mavica "CD" series (CD200, CD250, CD300, CD400 and CD1000) digicams. Their maximum capacity is ~165MB mm - millimeter, measurement to denote the focal length of a lens (i.e. 50mm)
MMC - MultiMedia Card, a flash memory card used in some digicams and MP3 players. It is identical in size and shape to the Secure Digital (SD) flash cards.
Moore’s Law. -Gordon Moore’s law that predicted that the number of transistors on a chip would double every 18 months.
MPEG.- A digital video format developed by the Motion Pictures Expert Group.
MPEG-HQX - Motion JPEG movie file created by year 2002 Sony cameras that incorporates the MPEG-HQ (high quality, full-screen) and the unlimited recording capability of MPEG-EX in 320x240 resolution. MPEG-VX - Motion JPEG movie file created by year 2003 Sony digicams. It is VGA resolution (640x480) at 16fps with audio and the length is limited only by available storage space. VX Fine is 30fps, very high quality. Multi-Pattern Metering - Exposure is determined by reading many different zones in the frame. This yields a more optimum exposure than those cameras using only a central zone metering system. Multi-Point Focusing - The autofocus systems uses SEVERAL different portions of the image to determine the proper focus. Multi Zone Focusing - Many digital cameras now offer multi zone focusing. The camera will automatically determine which zone (center, left, right, upper, lower) to use to perform the auto focusing. You no longer have to make sure that your subject is dead-center to be properly focused.
Multi-megapixel. An image or image sensor with over two million pixels.
Multiple exposure mode. A mode that lets you superimpose one image on top of another.
Multiple exposure. An image made up of two or more images superimposed in the camera.
NEF - Raw image data file format used by the Nikon digital SLR (D1x, D100, etc) and some Coolpix digicams. NEF means Nikon Electronic Format.
NiCad. Nickel cadmium battery.
NiMH. Nickel metal hydride battery.
Noise. Pixels on the image sensor that misread the light.
Noise Reduction - Some cameras that offer long shutter speeds (exceeding 1 second) usually have a noise reduction (NR) feature that is either automatic or can be enabled in the menu. This is to help eliminate random "hot" pixels and other image noise. NTSC - Term used to describe the 60 field video output (television) standard used in the U.S. and Japan. See also "PAL" and "Video Out"
Operating system. The program that controls the camera’s or computer’s hardware.
OEM - Original Equipment Manufacturer. Means that the piece of equipment is made by one company but labeled for and sold by another company.
OLED - Organic Light Emitting Diode - Newly developed display technology that could replace LCD. OLED does not require a backlight like LCD displays and therefore is more energy efficient which is important to battery-operated portable devices. It also offers increased contrast and a better viewing angle which means it can be more easily viewed in bright (sunlight) conditions. Optical Zoom - Means that the camera has a real multi-focal length lens, this is not the same as a "Digital Zoom" which magnifies the center portion of the picture. ORF - Olympus RAW format. The unprocessed image format created by Olympus E1, E10, E20, E300 SLRs and C-5050, C-5060, C-8080 Zoom cameras.
Orientation sensor.- A sensor that knows when you turn the camera to take a vertical shot and rotates the picture so it won’t be displayed on it’s side when you view it.
Overexposure-. Exposing the image sensor to more light than is needed to render the scene as the eye sees it. Results in a too light photograph.
PAL-. A European video out standard to display images on a TV screen.
Palette - A thumbnail of all available colors to a computer or devices. The palette allows the user to chose which colors are available for the computer to display. The more colors the larger the data and the more processing time required to display your images. If the system uses 24-bit color, then over 16.7 million colors are included in the palette.
Panorama. -A photograph with much wider horizontal coverage that a normal photograph, up to 360-degrees and more.
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.
Parallel port-. A port on the computer that is faster than a serial port but slower than SCSI, USB, or IEEE 1394 ports. Often used by printers and flash card readers.
PC card. -A card, in the case of cameras usually a storage device, that plugs into a slot in a notebook or hand-held computer. Originally called PCMCIA cards.
Photosite. A small area on the surface of an image sensor that captures the brightness for a single pixel in the image. There is one photosite for every pixel in the image.
PictBridge - PictBridge is a new standard for direct USB printing from digital cameras to inkjet and dye sub photo printers without the use of a computer
PIM - PRINT Image Matching - Epson's new standard of embedded color and printing information for digital cameras. Many of the camera manufacturers have joined with Epson and now embed the PIM information in the Exif header of the JPEG images created. Epson just announced at PMA 2002 the new Exif 2.2 standard incorporating their PIM info.
Pin-Cushioning - A common geometric lens distortion causing an acquired image to pucker toward the center, usually found at telephoto focal lengths
Pixelization.- An effect seen when you enlarge a digital image too much and the pixels become obvious.
Pixels. -The small picture elements that make up a digital photograph.
Plug-n-Play - An automated installation process used in MS Windows to connect peripherals to a computer. When new devices are plugged into the computer the computer recognizes the device and prompts the user to choose setup options and finish installation.
Polarizer - A photographic filter for eliminating glare and reflections. Just like your polarized sunglasses get rid of annoying glare, the polarizer filter does the same for your digicam. However - there are 2 types, linear and circular. Linear polarise screws up most auto focus systems on digicams. Therefore be sure you use a circular polarizer filter. It is also used to darken skies.
PPI - Pixels Per Inch - A measurement to describe the size of a printed image. The higher the number the more detailed the print will be.
Pre-Flash - Some digicams use a low-power flash before the main flash to set the exposure and white balance. This does not allow the use of a normal photo slave strobe as it will be triggered by the pre-flash.
Programmed AE - the camera picks the best shutter speed and aperture automatically, also called "Automatic" or "Point-n-Shoot" mode.
Progressive Scan - Term used to describe an image sensor that gathers its data and processes each scan line one after another in sequence. See also "Interlaced" for the other method. Prosumer - Refers to more expensive semi-professional digicams costing $1,000 and up. The average digicam is made for the consumer market and costs well under $1,000.
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 printer or modem.
Portrait mode-. Turning the camera to take a vertically oriented photograph.
Preview screen.- A small LCD display screen on the back of the camera used to compose or look at photographs.
QuickTime - A motion video standard created by Apple. QuickTime video sequences can contain an audio track and are stored as .MOV files. QVGA - Refers to a Quarter-VGA resolution (320 x 240) motion video sequences.
Rangefinder - The viewfinder on most cameras is a separate viewing device that is independent of the lens. Often mounted above and to the right or left of the lens. It exhibits a problem known as parallax when trying to frame subjects closer than five feet from the camera so it is advisable to use the color LCD when shooting closeups for this very reason.
RAW - RAW files store the unprocessed image data - at 12 bits per channel - from the camera's imaging chip to its memory storage device. Lossless compression is applied to reduce filesize slightly without compromising any quality. RAW image files must be processed with special software before they can be viewed or printed. The advantage is that you have the ability to alter the white balance, exposure value, color values, contrast, brightness and sharpness as you see fit before you convert this data into the standard JPEG or TIFF format. Professional digi-photographers import RAW image data directly into photo-editing programs like Photoshop CS (which comes with a Camera Raw import module that works with most popular RAW formats.).
Read out register.- The part of a CCD image sensor that reads the charges built up during an exposure.
Recycle time. -The time it takes to process and store a captured image.
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.
Red-eye. -An effect that causes peoples eyes to look red in flash exposures.
Refresh rate. -The time it takes the camera to capture the image after you press the shutter release.
Render - The final step of an image transformation or three-dimensional scene through which a new image is refreshed on the screen.
Resize - Usually means to take a large image and downsize it to a smaller one. Most graphic viewing and editing programs offer a Resize option for this purpose.
Resolution - The quality of any digital image, whether printed or displayed on a screen, depends in part on its resolution—the number of pixels used to create the image. More and smaller pixels adds detail and sharpens edges. Optical Resolution is an absolute number that the camera's image sensor can physically record. Interpolated Resolution adds pixels to the image using complex software algorithms to determine what color they should be. It is important to note that interpolation doesn't add any new information to the image - it just makes it bigger!
Camera makers often specify the resolution as: QVGA (320 x 240), VGA (640 x 480), SVGA (800 x 600), XGA (1024 x 768) or UXGA (1600 x 1200)
RGB - Means Red, Green and Blue - the primary colors from which all other colors are derived. The additive reproduction process mixes various amounts of red, green and blue to produce other colors. Combining one of these additive colors primary colors with another produces the additive secondary colors cyan, magenta and yellow. Combining all three produces white. RS-232 - Standard type of serial data interconnection available on most PC type computers. It's the slowest way to transfer image data from a camera. Most digicams made after 2001 do not use serial ports, they use the faster USB.
Removable media.- Storage media that can be removed from the camera.
Resolution, interpolated. -A process that enlarges an image by adding extra pixels without actually capturing light from those pixels in the initial exposure.
Resolution, optical.- The true resolution of an image based on the number of photosites on the surface of the image sensor.
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.
Saturation - The degree to which a color is undiluted by white light. If a color is 100 percent saturated, it contains no white light. If a color has no saturation, it is a shade of gray.
Scanner- An input device that uses light to read printed information including text, graphics, and bar codes, and transfers it into the computer in a digital format.
Scene Modes - Many digicams now have an exposure mode called SCENE where the user selects the best pre-programmed scene to suit the current shooting conditions. The camera will automatically change many settings to capture the best possible image.
SCSI port.- A port that’s faster than the serial and parallel ports but slower and harder to configure than the newer USB port. Also know as the Small Computer System Interface.
SD - Secure Digital card, a flash memory card used in digicams and MP3 players. It is identical in size and shape to the MultiMedia Card (MMC) flash cards. The difference being that SD card was designed to hold protected (copyrighted) data like songs. Not all cameras that use SD cards can use MMC cards so be sure to read your owner manual before buying additional cards
Self Timer - Preset time delay (2, 5 or 10 seconds) before the shutter fires. Allows the photographer to get into the picture without using a cable release or remote control. It is also great for taking macro shots as you don't touch the camera to trip the shutter and thus eliminates any camera shake.
Serial port. -A very slow port on the computer used mainly by modems. Many digital cameras come equipped with cable to download images through this port but it’s slow! Both parallel and USB ports are faster connections.
Short-focal-length lens (wide angle). A lens that provides a wide angle of view of a scene, including more of the subject area than does a lens of normal focal length.
Shutter Speed. The length of time the shutter is open and light strikes the image sensor.
Shutter. The device in the camera that opens and closes to let light from the scene strike the image sensor and expose the image.
Shutter Lag - The time between pressing the shutter and actually capturing the image. This due to the camera has to calculate the exposure, set the white balance and focus the lens.
Shutter-priority mode. An automatic exposure system in with you set the shutter speed and the camera selects the aperture (f-stop) for correct exposure.
Skylight Filter - This is an UltraViolet absorbing filter that helps overcome the abundance of blue in outdoor photographs. Not really necessary in digital photography as the camera's white balance system adjusts for the color temperature of the scene. We do use them to protect the camera's lens from scratching, fingerprints or dirt.
Slow Sync - A flash mode in some digicams that opens the shutter for a longer than normal period and fires the flash just before it closes. Used for illuminating a foreground subject yet allowing a darker background to also be rendered. Good for night time shots of buildings with people in the foreground. Often called Night Scene or Night Portrait mode.
SLR. A type of camera with one lens which is used both for viewing and taking the picture.
SmartMedia - (aka SSFDC), a flash memory card that consists of a thin piece of plastic with laminated memory on the surface and uses a gold contact strip to connect to the camera. SmartMedia cards are available from 4MB up to 128MB in size.
Spot Metering. Autoexposure is based on a meter reading of a small circle in the center of the viewfinder.
Smoothing - Averaging pixels with their neighbors. It reduces contrast and simulates an out-of-focus image. Spot Metering - The camera's auto exposure system is focused on a very small area in the center of the viewfinder to critically adjust the overall exposure value ONLY for that area.
SRF - Sony raw format filetype identifier. i.e. DSC00101.
SRF SSFDC - Solid State Floppy Disc Card Stitching - Combining a series of images to form a larger image or a panoramic photo. Requires special graphic software. Subtractive Color - Photographs and objects of nature create color by subtracting or absorbing certain wavelengths of color while reflecting other wavelengths back to the viewer. This is called subtractive color. Example - The common apple, it is seen as "red" by the human eye or a digital camera. The apple really has no color (light energy of its own), it merely reflects certain wavelengths of white light that cause us to see red and absorbs most other wavelengths. Color paintings, color photography and all color printing processes use the subtractive process to reproduce color. In these cases, the reflective substrate is canvas (paintings) or paper (photographs, prints), which is usually white. SuperCCD - Fujifilm's image sensor used in their line of digital cameras.
SVCD - "Super Video Compact Disc"A CD-ROM disc that contains high quality video and audio. Typically, a SVCD can hold about 35~45 minutes (650MB) of video and stereo-quality audio (depends on the data rate used for encoding). The video and audio are stored in MPEG-2 format, much like a DVD. SVCD video has better quality than VHS video.
SVGA - SuperVGA refers to an image resolution size of 800 x 600 pixels.
Tagged Image File Format. See TIFF.
Thru-the-lens. See TTL.
TIFF. A popular lossless image format used in digital photography.
Time-lapse photography. Taking a series of pictures at preset intervals to show such things as flower blossoms opening.
TTL. A camera design that let’s you compose an image while looking at the scene through the lens that will take the picture. Also called thru-the-lens.
TWAIN - Protocol for exchanging information between applications and devices such as scanners and digital cameras. TWAIN makes it possible for digital cameras and software to "talk" with one another on PCs. The word TWAIN is the abbreviation of "Technology Without An Industry Name."
Unbundling. When a dealer removes normally included items from a camera package and then sells them to you separately.
Underexposure. Exposing the film to less light than is needed to render the scene as the eye sees it. Results in a too dark photograph.
Unsharp Masking - A process by which the apparent detail of an image is increased; generally accomplished by the input scanner or through computer manipulation. USB - Universal Serial Bus - the data I/O port on most digicams and found on modern PC and Mac computers. Faster than the serial port. Up to 12Mb/s with v1.1 interfaces. USB 2.0 - The newest USB standard, close in throughput speed to FireWire now. Up to 400Mb/s.
It's important to note that many manufacturers are now "duping" the buying public by using statements like - "Equipped with a full-speed USB 2.0 interface" which unfortunately means that it's really just a USB 1.1 interface that will transfer data at up to 12Mb/s with newer USB 2.0 computer interfaces. What you should look for is a statement that says "Equipped with a high-speed USB 2.0 interface." The specification for a high-speed USB 2.0 interface is data transfer up to 400Mb/s.
UV Filter - This is an UltraViolet absorbing filter that helps overcome the abundance of blue in outdoor photographs. Not really necessary in digital photography as the camera's white balance system adjusts for the color temperature of the scene. We do use them to protect the camera's lens from scratching, fingerprints or dirt.
UXGA - Refers to an image resolution size of 1600 x 1200 pixels.
Upload. Sending a file from your computer to another device.
URL (Uniform Resource Locator). The address of a Web site.
USB port.- A high-speed port that lets you daisy-chain devices (connect one device to another).
VGA.- A resolution of 640 x 480.
Video card-. A card the fits into a computer’s expansion slot so you can edit digital video.
Viewfinder-. A separate window on the camera through which you look to compose images.
VGA - Refers to an image resolution size of 640 x 480 pixels. Video Out - Means the digicam has the ability to output its images on television screens and monitors using either NTSC or PAL format.
Viewfinder - The eye level device you look through to compose the image. Vignetting - A term that describes the darkening of the outer edges of the image area due to the use of a filter or add-on lens. Most noticeable when the zoom lens is in full wideangle
White balance. An automatic or manual control that adjusts the brightest part of the scene so it looks white.
X3 Image Sensor - Foveon's new image sensor for digital cameras that captures red, green and blue data at every pixel.
xD-Picture Card - A new flash memory card standard that was co-developed by Fujifilm and Olympus in mid-2002. Rumored to be replacing SmartMedia which has stalled at 128MB. xD is scheduled to go as large as 8GB in a form factor the size of a postage stamp.
XGA - Refers to an image resolution size of 1024 x 768 pixels.
ZLR - Zoom Lens Reflex, a term coined by Olympus to describe their fixed mount lens SLR type cameras. An SLR camera has interchangeable lenses, a ZLR has a non-removeable zoom lens. Zoom Lens - A variable focal length lens. . A lens that lets you change focal lengths on the fly.