Some Digital Camera Terminology
3x, 5x, 10x - Denotes the focal length ratio of a zoom lens (e.g. 35-105 is 3x, 38-380mm is 10x, divide the last number by the first).
See also "Digital Zoom" and "Zoom Lens" below.
AA cell - In the digital camera world this refers to the most common power source, the AA-size battery. See also "NiCd" and "NiMH" and check here: NiMH Batteries/Chargers
AC Power - Running your digital camera off the wall outlet power rather than by battery power. Usually means purchasing optional AC power adapter.
Add-On Lens - Some lenses have filter threads on the front edge that allow you to mount an auxiliary wide angle or telephoto lens in addition to the standard lens.
AE - Auto Exposure, a system for automatically setting the proper exposure according to the existing light conditions. There are three types of AE systems:
Programmed: where the camera picks the best shutter speed and aperture automatically;
Aperture Priority: the user chooses an aperture value and the shutter speed is automatically determined by lighting conditions; and
Shutter Priority: the user chooses a shutter speed and the aperture is automatically determined by lighting conditions
AE Lock - The ability to hold the current exposure settings and allow you to point the camera elsewhere before capturing the image. This is usually accomplished by half-pressing the shutter button and keeping it at that position until you're ready to capture the image.
AF - Auto Focus. A system that automatically focuses the camera lens.
Algorithm - A mathematical routine that solves a problem or equation. In imaging, the term is usually used to describe the set of routines that make up a compression or colour management program.
Anti-Shake - Konica Minolta's "Anti-Shake" feature is the mechanical shifting of the imager to compensate for camera movement and minimise blurring at lower shutter speeds. Putting this type of image stabilisation in the camera body of a dSLR means that it doesn't have to built into the lenses and therefore it makes them lighter and less expensive. See also "Optical Image Stabilisation"
Aperture - The lens opening formed by the iris diaphragm inside the lens.
Aperture Priority AE - Exposure is calculated based on the aperture value chosen by the photographer. This allows for depth of field (DOF: Range of focus) control - large aperture = shallow DOF and a small aperture = deep DOF.
Aspect Ratio - The ratio of horizontal to vertical dimensions of an image. The most common aspect ratio in digital cameras is 4:3 so that images "fit" properly on computer screens (800x600, 1024x768, 1280x1024). Some cameras offer a 3:2 mode so that you can print "perfect" 4x6" prints with no cropping necessary.
(35mm film is 3:2, TV sets are 4:3, HDTV screens are 16:9)
Aspherical Lens - A lens whose edges have been flattened so that it is not a perfect sphere, produces a superior image.
Automatic Exposure - The camera automatically adjusts the aperture or shutter speed or both for the proper exposure.
Autofocus - The camera lens focuses automatically, usually when the shutter release is half-pressed.
AVI - Movie clip in Windows' AVI format. See "Movie clip"
AWB - Automatic White Balance. A system for automatically setting the white balance in today's digital cameras. See also "White Balance"
B&W - Term used to mean black and white
Back Lit - The subject is heavily lit from behind which generally causes it to be underexposed unless you use critical spot metering or use your flash
Backlight - The illumination for a colour LCD display. Early colour LCD used high voltage fluorescent lamps, newer LCDs now use white LEDs which are much more energy efficient.
Barrel Distortion - A common geometric lens distortion causing an acquired image to pucker toward the centre and be "rounded" along the outer edges.
Bitmap - The method of storing information that maps an image pixel, bit by bit. There are many bitmapped file formats, .bmp, .pcx, .pict, tiff, .tif, .gif, and so on. Most image files are bit mapped. This type of file gives you the 'jaggies', when examined closely you can see the line of pixels that create the edges.
Bleed - Printing term referring to an image or linked area that extends to the edge of the printed piece.
Blue Tooth - The new wireless standard for connecting cameras, PDAs, laptops, computers and cell phones. Uses very high frequency radio waves. Blue Tooth devices when in-range (less than 30 feet) of each other easily establish a connection.
BMP - BitMapped graphic file format popular with Windows computers. This is an uncompressed file format like TIFF.
Borderless - Means a photo print with no border around it. Old term for this was full-bleed printing.
Bracketing - see Exposure Bracketing
Brightness - The value of a pixel in an electronic image, representing its lightness value from black to white. Usually defined as brightness levels ranging in value from 0 (black) to 255 (white).
Buffer - A temporary storage area usually held in RAM. The purpose of a buffer is to act as a temporary holding area for data that will allow the CPU to manipulate data before transferring it to a device. Also see DRAM Buffer
Burst Mode - The ability to rapidly capture images as long as the shutter button is held down. Also called Continuous frame capture.
Byte - An ensemble of eight bits of memory in a computer.
Calibration - The act of adjusting the colour of one device relative to another, such as a monitor to a printer, or a scanner to a film recorder. Or, it may be the process of adjusting the colour of one device to some established standard.
Card Reader - A device that you insert flash memory cards into to transfer the data to the computer. Much faster than the serial port! For more: Memory Card Readers
CCD - Charged Coupled Device, a light sensitive chip used for image gathering. In their normal condition these are grey scale devices. To create colour a colour pattern is laid down on the sensor pixels, using a RGBG colour mask (Red, Green, Blue, and Green) The extra Green is used to create contrast in the image. The CCD Pixels gather the colour from the light and pass it to the shift register for storage. CCDs are analog sensors, the digitising happens when the electrons are passed through the A to D converter. The A to D converter converts the analog signal to a digital file or signal. See also "CMOS" below
CD - CompactDisc - read only storage media capable of holding 650MB of digital data.
CD-R - CompactDisc Recordable - a CD that you can write to once that can not be erased but can be read many times, holds 650~700MB of digital data.
CD-RW - CompactDisc ReWriteable - the newest kind of CD-R that can be erased and re-used many times, holds about 450MB of data.
Centre-Weighted - A term used to describe an auto exposure system that uses the centre portion of the image to adjust the overall exposure value. See also "Spot Metering" and "Matrix metering"
CF - see CompactFlash
Channel - One piece of information stored with an image. True colour images, for instance, have three channels-red, green and blue.
Chromatic Aberration - Also known as the "purple fringe effect." It is common in two Megapixel and higher resolution digital cameras (especially those with long telephoto zoom lenses) when a dark area is surrounded by a highlight. Along the edge between dark and light you will see a line or two of purple or violet coloured pixels that shouldn't be there.
CIFF - Camera Image File Format, an agreed method of digital camera image storage used by many camera makers.
CMOS - Complementary Metal Oxide Semiconductor - Another imaging system used by digital cameras. It is not as popular as CCD but the future promises us even better digital cameras based on CMOS sensors due to the lower amount of power consumption versus the typical CCD device.
CMS - Colour Management System. A software program (or a software and hardware combination) designed to ensure colour matching and calibration between video or computer monitors and any form of hard copy output.
CMYK - Cyan, Magenta, Yellow, black; These are the printer colours used to create colour prints. Most colour printers, Ink-Jet, Laser, Dye-Sublimation and Thermal printers use these as their printer colours. (This is one of the colour management problems for computers. Converting RGB files to CMYK files cause's colour shifts.) When used by a printer the CMYK is also known as a reflective colour since it is printed on paper, or reflective films.
Colour Balance - The accuracy with which the colours captured in the image match the original scene.
Colour Correction - The process of correcting or enhancing the colour of an image.
Colour Depth - Digital images can approximate colour realism, but how they do so is referred to as colour depth, pixel-depth, or bit depth. Modern computer displays use 24-bit True Colour. It's called this because it displays 16 million colours, about the same number as the human eye can discern.
CompactFlash (CF) - This used to be the most common type of digital camera flash memory storage (now superceded by secure digital SD cards). It is removable, small and commonly available in sizes from 16MB up to 8GB.
CF Type I the original 3.3mm high card
CF Type II cards and devices that are 5mm high.
Type I devices are all solid state but Type II devices include the IBM/Hitachi Microdrive, a miniature, rotating hard drive.
and click here: Flash Memory Cards
Compression - A digital photograph creates an image file that is huge, a low-resolution 640x480 image has 307,200 pixels. If each pixel uses 24 bits (3 bytes) for true colour, a single image takes up about a megabyte of storage space. To make image files smaller almost every digital camera uses some form of compression. See the "JPG" entry below.
Continuous Autofocus - (Continuous-AF) The autofocus system is full-time and works even before the shutter release is pressed.
Contrast - A measure of rate of change of brightness in an image.
CR-V3 - This is a 3V lithium battery used in many Olympus brand (and other) digital cameras. It lasts much longer than alkaline but it is also more costly. See CR-V3 batteries here.
CRW / CR2 - The raw CCD file format used by Canon digital cameras. Abbreviated from CanonRaW. Canon also has newer CR2 raw format as well.
Dark Frame - A noise reduction process whereby a camera takes a second exposure of a black frame after the camera takes a long exposure (1/2-second or longer) image. The image "noise" is easily identified in the black frame shot and is then electronically removed from the actual image. This helps reduce the amount of hot pixels that normally show up in long exposure shots from digital cameras.
DC - Direct Current. Battery power as in 9v DC battery
Decompression - The process by which the full data content of a compressed file is restored.
Dedicated Flash - Describes an electronic flash that is made to be used only with a specific model of camera. Canon, Nikon, Olympus and other cameras have specific electrical contacts in the hot shoe to pass TTL-metering and AF range data to/from the flash unit. You can not use a dedicated Canon flash on a Nikon camera for example.
Densitometer - A tool used to measure the amount of light that is reflected or transmitted by an object.
Depth of Field - depth of field (DOF) The range of sharp focus. Controlled by the focal length and aperture opening of the lens. A large aperture yields shallow DOF. Smaller apertures yield deeper DOF. Here's an online - DOF Calculator
(Be sure to follow the directions when calculating the DOF for your digital camera's lens -- it is NOT calculated using the 35mm equivalent (i.e. 35-105mm) focal length often quoted in our reviews -- you must use the real focal length of the smaller digital lens. The site linked above has a listing of popular cameras and their real lens specifications.)
Digital Film - Term used to describe solid state flash memory cards, commonly called memory cards.
Digital Image Stabilisation (DIS) - An electronic method of minimising the effect of camera shake during video recording. The most common method of DIS is to capture a larger frame and electronically crop the edges depending on the direction of camera movement. See also "Anti-Shake" and "Optical Image Stabilisation"
Digital Zoom - A digital magnification of the centre 50% of an image. Digital zooms by nature generate less than sharp images because the new "zoomed" image has been interpolated.
Digitisation - The process of converting analogue information into digital format for use by a computer.
Diopter Adjustment - Adjusts the optical viewfinder's magnification factor to suit the eyesight of the user. Look for a knob or dial next to or beneath the viewfinder's eyepiece. Not all cameras have this feature.
DOF - Abbreviation for Depth of Field (see above).
Download - Transfer image data from the camera to the computer using a cable attached to either the serial port (slow) or USB port (faster.)
DPI - Dots per Inch. A measurement value used to describe either the resolution of a display screen or the output resolution of a printer.
DPOF - Digital Print Order Format. Allows you to embed printing information on your memory card. Select the pictures to be printed and how many prints to make. Some photo printers with card slots will use this info at print time. Mostly used by commercial photo finishers or those Kodak kiosks you find in the mall.
DRAM - Dynamic Random Access Memory. A type of memory that is volatile - it is lost when the power is turned off.
DRAM Buffer - All digital cameras have a certain amount of fixed memory in them to facilitate image processing before the finished picture is stored to the flash memory card. Cameras that have a burst mode have much larger DRAM buffers, often 32MB or larger. This also makes them more expensive.
DSLR - Digital SLR (Single Lens Reflex) camera. Interchangeable lens digital camera. Manufacturers include Canon, Fuji, Kodak, Nikon, Olympus, Pentax and Sigma. See our DSLR Cameras.
DVD - "Digital Versatile Disc"
DVD is DVD-Video recorded on a DVD-R or DVD-RW disc, which contains superior quality video (MPEG-2) and audio. Typically, a DVD can hold more than one hour of video.
DVD Video Parameter Settings
Frame Size: 720x480 (NTSC) or 720x576 (PAL)
Frame Rate: 29.97 frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: 4~8 Mbps CBR or VBR (Constant/Variable Bit Rate)
Audio Settings: Stereo, 48 kHz and 192~384 kbps MPEG audio
Dye Sub - Dye Sublimation is a printing process where the colour dyes are thermally transferred to the printing media. Dye sub printers use the CMYK (cyan, magenta, yellow, black) colour format and have either three ribbons (cyan, magenta and yellow) or high-end printers have four CMY plus a blacK. The paper is run in and out of the printer four times, once for each colour and then a fourth time when a protective overcoat is applied. Dye sub is continuous tone printing, it prints tiny square dots each of which is denser in the centre and lighter on the edges. Dye sub prints rival conventional photographs in both their colour gamut and longevity with water and UV resistant qualities.
For the sake of accuracy we must state that most printers today that claim to be dye sub type printers are actually dye diffusion. The complete technical name for this process is Dye Diffusion Thermal or "D2T" printing. To achieve true sublimation printing requires a laser to vaporise the dye material. The common 4x6" dye sub prints like the Canon CP printers heat the dye material with a thermal print-head and use pressure rollers to push the ribbon into contact with the paper and then diffusion occurs. For our Dye Sub printers click here.
Dynamic Range - A measurement of the accuracy of an image in colour or gray level. More bits of dynamic range results in finer gradations being preserved.
EPP - Enhanced Parallel Port - the newer hi-speed, bidirectional printer port on modern computers. Some older digital cameras and scanners use the EPP port to transfer data.
ERI-JPEG - Extended Range Imaging Technology, a new file format used in Kodak professional digital cameras. This proprietary technology offers an innovative image file format similar to a JPEG, but with the dynamic range and colour gamut information of raw DCR camera files. Extended Range Imaging Technology files allow you to easily open, edit, and print JPEG files within your JPEG workflow. Your JPEG files are captured directly in the camera. With ERI, you'll have the extensive editing, colour balance, and colour compensation capabilities of RAW digital negatives for applying to your JPEG files.
E-TTL - Canon's Evaluative-TTL exposure system that uses a brief pre-flash before the main flash to calculate the exposure index.
EV - Exposure Value, a very complex thing but in the digital camera world it usually means the ability to override the auto exposure system to lighten or darken an image.
EVF - Electronic ViewFinder, a small colour LCD with a magnified lens that functions as an eye level viewfinder. Usually found on video camcorders but they have been showing up on super-zoom digital cameras where optical viewfinders are impractical. (Canon Pro90, Fuji 2800Z, Olympus C-2100, Nikon Coolpix 5700).
EXIF - EXIF (Exchangeable Image File format) refers to the embedded camera and exposure information that a digital camera puts in the header of the JPG files it creates. Many graphic programs (Photoshop, ThumbsPlus, Qimage Pro, CameraAid) can read and display this information.
Exif Print - Exif Print (Exif 2.2) is a new worldwide printer independent standard. Under Exif 2.2, the digital still camera can record data tags for specific camera settings and functions such as whether the flash was on or off, if the camera was in landscape, portrait or night scene mode, etc. Referencing some or all of this information, an Exif Print compatible application can process digital camera images intelligently based on specific camera settings and the shooting environment.
Exposure - The amount of light that reaches the image sensor and is controlled by a combination of the lens aperture and shutter speed.
Exposure Bracketing - the camera automatically takes a series of 3 or 5 pictures and slightly varies the EV for each frame. This insures that at least one of the pictures will be as close to perfectly exposed as possible.
Exposure Compensation - Lighten or darken the image by overriding the exposure system. Also known as EV Compensation.
f-stop - A numerical designation that indicates the size of the aperture. It is inversely proportional as a smaller number like F2.8 is a large opening and a large number like F16 is a relatively small opening.
Field of View - please see FOV below.
File - A collection of information, such as text, data, or images saved on a disk or hard drive.
File Format - A type of program or data file. Some common image file formats include TIFF, JPEG, and BMP.
Fill Flash - The most popular use for flash is to fill (lighten) harsh shadows in sunlit outdoor portraits. Most cameras with built-in flash units offer both auto-flash and fill-flash modes. In auto-flash, the flash unit automatically fires when needed (i.e., in dim lighting). In fill-flash mode the flash will fire for every shot, regardless of light level. This is the mode to use to fill-in those harsh shadows in sunlit portraits (in auto-flash mode, the flash probably won’t fire due the the bright ambient light level).
FireWire - Also known as "iLink" and officially designated as the IEEE 1394 protocol. A high-speed data interface now being used on digital camcorders and some high-end digital still cameras.
Firmware - An often-used micro program or instruction set stored in ROM. Usually refers to the ROM-based software that controls a unit. Firmware is found in all computer based products from Cameras to Digital Peripherals.
Fixed Aperture - Normally when a zoom lens goes from wide angle to telephoto the aperture changes. If the camera has an option to fix the aperture value then it remains constant regardless of focal length.
Fixed Focal Length - A term that describes a non-zoom lens, it is fixed at a given focal length and is not variable.
Fixed Focus - A lens that is preset to a given focus distance, it has no auto focus mechanism, set to give the camera the maximum depth of field
Flash - A built-in flash supplies auxiliary light to supplement natural or available lighting conditions often resulting in better colour, better exposure, and improved picture sharpness.
Flash Memory - This is the "film" for digital cameras, it can be erased and reused many times. It is non volatile memory, data is preserved even when it is not under power. They are several major types used in digital cameras; CompactFlash, SmartMedia, Secure Digital (SD), xD cards (Fuji and Olympus digital cameras), MMC and RS-MMC.
Focal Length - A lens' angle of view, most commonly indicated as wide angle, normal or telephoto. Usually compared to a 35mm camera's lenses as in "the camera has a wide angle lens equivalent to a 38mm lens on a 35mm camera." See also "Zoom Lens"
Focus Assist - Some cameras employ a visible or invisible (infrared) lamp to illuminate the subject so the auto focus can work in low light or total darkness.
Focus Lock - Pre-focusing the camera and then moving it to re-compose the image before capturing it. Accomplished by half-pressing the shutter button and keeping it held at that position while moving the camera to another point before pressing it all the way to capture the image.
FOV - Field of View - The area covered by the lens' angle of view. This is important to those with a digital SLR camera using lenses designed for 35mm film cameras. The manufacturers specify the FOV for these lenses when used on a 35mm camera but not when they're used on a modern dSLR camera.
FPX - FlashPiX - Trade name for a new multi-resolution image file format jointly developed and introduced in June 1996 by Kodak, HP, Microsoft and Live Picture.
Frame - One of the still pictures that make up a video.
Frame rate - The number of frames that are shown or sent each second. Live action relates to a frame rate of 30 frames per second.
Full Bleed - Printing term used when an image or inked area extends to the edge of all four sides of the printed piece. Better known as "borderless" in today's world of inkjet photo printers.
Gamma - A measure of the amount of contrast found in an image according to the properties of a gradation curve. High contrast has high gamma and low contrast low gamma.
Gamma Correction - In reference to displaying an image accurately on a computer screen, Gamma correction controls the overall brightness of an image. Images which are not properly corrected can look either bleached out, or too dark. For more info on gamma, go here
Gamut - The range of colours that are available in an image or output process. It is generally used in describing the capabilities of a printer to reproduce colours faithfully and vibrantly - i.e. "The xxxxx printer has a wide colour gamut."
GIF - A graphic file format used mainly for Web graphic or small animated files. Not good for photos as it only contains a maximum of 256 colours.
Gigabyte (GB) - A measure of computer memory or disk space consisting of about one thousand million bytes (a thousand megabytes). The actual value is 1,073,741,824 bytes (1024 megabytes).
Gradation - A smooth transition between black and white, one colour and another, colour and no colour.
Gray Level - The brightness of a pixel. The value associated with a pixel representing it's lightness from black to white. Usually defined as a value from 0 to 255, with 0 being black and 255 being white.
Gray Scale - A term used to describe an image containing shades of gray rather than colour. Most commonly referred to as a black and white photo.
Guide Number - The output power rating of a electronic flash unit.
HAD CCD - Sony's latest CCD imager, HAD = Hole Accumulation Diode
Halftone Image - An image reproduced through a special screen made up of dots of various sizes to simulate shades of gray in a photograph. Typically used for newspaper or magazine reproduction of images but it is also how today's inkjet printers work. Halftoning or dithering are the methods used to produce a smooth gradation of colour versus distinct bands of colour or moirè patterns.
HD - Hard drive (aka HDD), the internal, large-capacity data storage unit in today's PC computers.
HDTV - High Definition Television. New video "standard" that will resolve 1,125 lines in the United States instead of the traditional 525 lines of the NTSC standard. The aspect ratio is 16:9 versus 4:3 of regular TV sets.
Histogram - A bar graph analysis tool that can be used to identify contrast and dynamic range of an image. Histograms are found in the more advanced digital cameras and software programs (graphic editors) used to manipulate digital images. The histogram shows a scale of 0 - 255 (left to right) with 0 being black and 255 being white.
Hot Shoe - A flash connector generally found on the top of the camera that lets you attach a flash unit and trigger it in sync with the shutter.
Hologram Laser AF - Sony introduced a new laser-assisted auto focus system on the Cyber-shot DCS-F707 that uses a safe Class 1 laser to paint a grid on the subject that makes the auto focus fast and accurate. Also found on the DSC-F717, F828, V1 and V3 cameras.
Hue - A term used to describe the entire range of colours of the spectrum; hue is the component that determines just what colour you are using. In gradients, when you use a colour model in which hue is a component, you can create rainbow effects.
i-TTL - Nikon's flash exposure system.
ICC Profile - The International Colour Consortium, a group that sets standard guidelines for colour management in the imaging world. Click here to read their FAQs about colour management and ICC profiles and the like. Most printers, monitors and scanners as well as digital cameras, usually come with a driver disc for Windows and Mac systems that includes ICC profiles for the particular device. Colour profiles simply let one piece of hardware or software "know" how another device or image created its colours and how they should be interpreted or reproduced.
iESP - Olympus' exposure metering system.
iLink - Sony's term for IEE-1394 FireWire data port found on Sony camcorders.
Image Processing - Capturing and manipulating images in order to enhance or extract information.
Image Resolution - The number of pixels per unit length of image. For example, pixels per inch, pixels per millimeter, or pixels wide.
Image Sensor - A traditional camera exposes a piece of light-sensitive film, digital cameras use an electronic image sensor to gather the image data. See "CCD" and "CMOS" as well as "Interlaced" and "Progressive Scan"
Image Stabilisation - An optical or digital system for removing or reducing camera movement in telephoto zoom lenses. Usually found only on extremely long focal length lenses such as the 10X lens on Sony and Olympus. Can also be found on Panasonic 12X Leica zoom lens. Canon has has appended an "IS" abbreviation to its Powershot S1_IS and S2_IS series of digital cameras.
InfoLITHIUM - Sony's "smart" lithium rechargeable battery pack. It has a chip inside that tells the camera how long (in minutes) it will last at the current discharge rate.
Inkjet - A type of printer that sprays dots of ink onto paper to create the image. Modern inkjet printers now have resolutions of up to 2880dpi and create true photo-quality prints.
Interpolated - Software programs can enlarge image resolution beyond the actual resolution by adding extra pixels using complex mathematic calculations. See "Resolution" below
Intervalometer - Fancy term for Time-Lapse. Capture an image or series of images at preset intervals automatically.
Interval Recording - Capturing a series of images at preset intervals. Also called time-lapse.
IR - InfraRed (aka IrDA) uses an invisible (to humans) beam of light to either wirelessly control a device or as a method of transferring data from camera to computer (or printer) without cables. Some cameras also employ infrared in the auto focusing system.
ISO - The speed or specific light-sensitivity of a camera is rated by ISO numbers such as 100, 400, etc. The higher the number, the more sensitive it is to light. As with film, the higher speeds usually induce more electronic noise so the image gets grainier. ISO is the abbreviation for International Standards Organisation. (In the good old days it was known as the "ASA film speed.")
"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-colour 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 2000. It will feature higher compression but with less image quality loss.
KB - Can be used to mean either a keyboard for a computer or more commonly "KB" means a kilobyte of data.
Landscape Mode - Holding the camera in its normal horizontal orientation to capture the image. See Portrait Mode.
LCD - Liquid Crystal Display. Two types: (1) a TFT high-resolution colour display device like a tiny TV set. (2) A monochrome (B&W) information display using black alphanumeric characters on a grey/green background. Note: like TV and computer screens, LCD measurements are taken on the diagonal. 2 inch, 2.5 inch sized LCD is the measurement from opposite corners.
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 digital cameras 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.
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 colour aliasing (moire) problems.
Macro - The ability of a lens to focus very close (less than 8") for taking pictures of small objects at a 1:1 ratio.
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. 2500mAh cell). It stands for milliAmperehour.
Matrix metering - In most digital cameras there is a matrix metering option which uses 256 areas of the frame to calculate the best overall exposure value. see also: "Spot metering" and "Centre-weighted"
MB - MegaByte, memory term meaning 1024 KiloBytes. Used to denote the size of a flash memory card such as 4MB, 8MB etc. (MB [megabyte] is often confused with Mb [megabit], there's 8 bits in a byte so 256Mb = 32MB.)
MD - MiniDisc - Digital recording media like a small floppy disc. This is common for audio data and has been used on several digital cameras sold in Japan and Europe but not in the U.S. yet.
Megapixel - CCD resolution of one million pixels. digital cameras 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 Megapixel
1600 x 1200 pixels = 2 Megapixels
2048 x 1536 pixels = 3 Megapixels
2272 x 1704 pixels = 4 Megapixels
2560 x 1920 pixels = 5 Megapixels ... and so on
Memory Stick - A flash memory card standard from Sony. They resemble a stick of gum. Used in Sony cameras prior to 2003.
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.
Metering - Used to calculate the exposure from the existing light conditions. See: "Matrix Metering," "Spot metering" and "Centre-weighted"
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) digital cameras. 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 digital cameras and MP3 players. It is identical in size and shape to the Secure Digital (SD) flash cards.
Moirè - A visible pattern that occurs when one or more halftone screens are misregistered in a colour image. Often produces a coloured checkerboard or rainbow pattern.
MOV - Apple QuickTime MOVie file format. See "Movie clip"
Movie clip - A sequence of motion captured in AVI, MOV or MPEG format. Some digital cameras can capture short movie sequences, some can also record the sound.
Motion JPEG - A video sequence composed of a sequence of JPEG compressed images. Abbreviated to MPEG (see MEG below).
MP - Abbreviation for MegaPixel, i.e. 5MP or 5MPixel
MPEG - Motion JPEG movie file. See "Movie clip"
The digital video compression standard agreed upon by the Motion Picture Expert Group, from the motion picture-computer industry. MPEG-2 is used by most camcorders and MPEG-4 with a higher compression ratio is popular with digital cameras that offer motion video recording.
MPEG-EX - Motion JPEG movie file created by Sony cameras. This was the first motion video recording sequence mode that was limited in length only by the amount of available storage space.
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 digital cameras. 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 (centre, left, right, upper, lower) to use to perform the auto focusing. You no longer have to make sure that your subject is dead-centre to be properly focused.
NEF - Raw image data file format used by the Nikon digital SLR (D1x, D100, etc) and some Coolpix digital cameras. NEF means Nikon Electronic Format.
NiCd - Nickel Cadmium (aka Nicad), a type of rechargeable battery. Nicad was the original type of rechargeable battery and has been pretty much replaced by the NiMH type.
NiMH - Nickel-Metal Hydride, a type of rechargeable battery. NiMH is the more modern type of rechargeable battery and has been touted as having no memory effect as is common with Nicad type batteries when they are charged before they have been fully discharged. Check here: NiMH Batteries/Chargers
Noise - Pixels in your digital image that were misinterpreted. Usually occurs when you shoot a long exposure (beyond 1/2-second) or when you use the higher ISO values from 400 or above. It appears as random groups of red, green or blue pixels.
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". In Australia the standard is PAL. Most recent equipment switches automatically between NTSC and PAL.
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 Image Stabilisation (OIS) - Most commonly found in higher-end dSLR telephoto and tele-zoom lenses. OIS uses a spinning gyroscope and a lens element to counteract camera movement and handshake at longer focal lengths and lower shutter speeds. OIS is also incorporated into fixed-lens digital cameras, first seen on the Olympus C-2500L and now being used extensively by Panasonic on their "FZ" series of 12x super-zoom digital cameras.
Optical Viewfinder - An eye level viewfinder that is used to compose the photograph. Recently this has been left off new cameras as the cameras become smaller and LCD screens larger (and more power efficient).
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 centre portion of the picture and degrades the image.
ORF - Olympus RAW format. The unprocessed image format created by Olympus E1, E10, E20, E300, E500 SLRs and C-5050, C-5060, C-7070, C-8080 Zoom cameras.
Orientation Sensor - A special sensor in some cameras that "knows" when your turn the camera in portrait orientation to take a vertical shot and "tells" the camera to display it that way later when viewed on the TV screen during playback.
Overexposure - An image that appears too light. All the highlights and colours are totally lost and usually unrecoverable even by software.
PAL - The 50 field video format used primarily in Australia and Europe and other places outside of the U.S. and Japan. See also "NTSC" and "Video Out"
Palette - A thumbnail of all available colours to a computer or devices. The palette allows the user to chose which colours are available for the computer to display. The more colours the larger the data and the more processing time required to display your images. If the system uses 24-bit colour, then over 16.7 million colours are included in the palette.
Panorama - Capturing a series of images to create a picture wider than what you could capture in a single image. Requires special "stitching" software to combine and blend the images into one finished image.
Parallax - An effect seen in close-up photography where the viewfinder does not see the same as the lens due to the offset of the viewfinder and the lens. This is a non-issue if using the LCD as a viewfinder or if your camera is a SLR type.
PC - In camera terms it denotes a type of flash synch connector, popular on most film cameras.
PC - In computer terms it means a Personal Computer as in IBM-PC
PC Card - Refers to a credit card-sized device which can be a flash memory card, a network card, a modem or even a hard drive. Comes in two flavors: Type I/II which is a single slot height and Type III which requires a double-height card slot.
PCMCIA - The card slots found on laptop computers to use PC Cards. There are PCMCIA adapters for CompactFlash, SmartMedia, Secure Digital, MultiMediaCard and Memory Stick flash cards.
PictBridge - PictBridge is the standard for direct USB printing from digital cameras to inkjet and dye sub photo printers without the use of a computer. Almost all new digital cameras are PictBridge compatible.
Pin-Cushioning - A common geometric lens distortion causing an acquired image to pucker toward the centre, usually found at telephoto focal lengths. See examples of it at Andromeda's LensDoc page.
Pixel - The individual imaging element of a CCD or the individual output point of a display device. This is what is meant by the figures 640x480, 800x600, 1024x768, 1280x960 and etc when dealing with the resolution of a particular digital camera. Higher numbers are always better!!
Pixelisation - 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 "pixelisation" of the image. Also known as the "jaggies".
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 recognises the device and prompts the user to choose setup options and finish installation.
Polariser - A photographic filter for eliminating glare and reflections. Just like your polarised sunglasses get rid of annoying glare, the polariser filter does the same for your digital camera. However - there are 2 types, linear and circular. Linear is for film only, it screws up most auto focus systems on digital cameras. Therefore be sure you use a circular polariser filter. It can also be used to darken skies.
PNG - An image file format. PNG stands for Portable Network Graphics. It is a compressed file format similar to JPG.
Point and Shoot - A term used for a simple, easy to use camera with a minimum of user controls. Generally the user turns the camera on, aims it at the subject and presses the shutter button. The camera does everything automatically.
Polarising Filter - A filter than helps eliminate light reflections by limiting the angle of light that reaches the lens. There are two types: Linear and Circular. Linear type filters should not be used with digital cameras as they hinder the auto focus system. The circular type filters can be rotated to adjust to the light angle needed.
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 digital cameras 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 digital cameras costing $1,000 and up. The average digital camera is made for the consumer market and costs well under $1,000.
QuickTime - A motion video standard created by Apple. They have an entire QuickTime web site to explain it. 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.
RAM - Random Access Memory . The most common type of computer memory; where the CPU stores software, programs, and data currently being used. RAM is usually volatile memory, meaning that when the computer is turned off, crashes, or loses power, the contents of the memory are lost. A large amount of RAM usually offers faster manipulation or faster background processing.
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 colour LCD when shooting close-ups 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 file size 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, colour values, contrast, brightness and sharpness as you see fit before you convert this data into the standard JPEG or TIFF format. Professional digital 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.)
Red-Eye - An effect caused by an electronic flash reflecting off of the human eye and making it look red. Compact cameras with the flash located close to the lens suffer the worst from this problem. Pro photographers use a bracket to hold an external flash unit above and off to the side of the lens to eliminate red-eye. There are also software options to remove red-eye.
Red-Eye Reduction Mode - A special flash mode whereby a pre-flash or a series of low-powered flashes are emitted before the main flash goes off to expose the picture. This causes the pupil in the human eye to close and helps eliminate red-eye.
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 colour 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)
RF - Range Finder - a type of camera viewfinder that uses one lens to frame your subject and another lens to capture the image. See "SLR" for the other type.
RGB - Means Red, Green and Blue - the primary colours from which all other colours are derived. The additive reproduction process mixes various amounts of red, green and blue to produce other colours. Combining one of these additive colours primary colours with another produces the additive secondary colours 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 digital cameras made after 2001 do not use serial ports, they use the faster USB.
Saturation - The degree to which a colour is undiluted by white light. If a colour is 100 percent saturated, it contains no white light. If a colour has no saturation, it is a shade of gray.
Scanner - An optical device that converts images - such as photographs - into digital form so they can be stored and manipulated on computers. Different methods of illumination transmit light through red, green and blue filters and digitise the image into a stream of pixels.
Scene Modes - Many digital cameras 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. For an overview of photographic scene modes, click here.
SD - Secure Digital card, a flash memory card used in digital cameras and MP3 players. It is identical in size and shape to the MultiMedia Card (MMC) flash cards. The difference being that SD cards were 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.
Secure Digital - Secure Digital. See "SD" above.
SDHC - SDHC high capacity card specification will allow manufacturers to develop a new world of digital devices. SDHC (SD High-Capacity) Memory Card based on the new SD Specification Version 2.00. This latest specification was established to meet the growing demand for HD (High Definition) video and high-resolution image recording now used in many SD-enabled devices. Camera manufacturers may issue firmware updates for existing cameras which wouls allow these cameras to use the new high capacity SDHC cards. SDHC cards have the same form factor as SD cards but allow for capacities of 4 GB or greater (by using sector addressing rather than byte addressing).
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.
Sepia - The (brown) mono-toned images from the "bygone era" now often found as a special image effect on some digital cameras.
Serial Port - Same as "RS-232" above.
Shutter - The physical device that opens and closes to let light from the scene strike the image sensor. digital cameras use both electronic and mechanical shutters.
Shutter Lag - The time between pressing the shutter and actually capturing the image. This is due to the camera having to calculate the exposure, set the white balance and focus the lens. Reduce the lag by half depressing the shutter (pre-focus).
Shutter Priority AE - the user chooses a shutter speed and the aperture is automatically determined by lighting conditions. Shutter speed priority is used to control motion capture. A fast shutter speed stops fast action, a slow shutter speed blurs a fast moving subject.
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 colour 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 digital cameras 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 - Single Lens Reflex - Means the camera has a viewfinder that sees through the lens (TTL) by way of a 45°-angled mirror that flips up when the shutter fires and allows the light to strike the image sensor (or film).
SmartMedia - SmartMedia memory cards are available from 64MB up to 128MB in size. They are no longer used in current model digital cameras and have been difficult to supply in recent times. They are almost obsolete.
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 centre of the viewfinder to critically adjust the overall exposure value ONLY for that area.
see also: "Centre-weighted" and "Matrix metering"
SRF - Sony raw format filetype identifier. i.e. DSC00101.SRF
SSFDC - Solid State Floppy Disc Card - See "SmartMedia" above
Stitching - Combining a series of images to form a larger image or a panoramic photo. Requires special graphic software.
SuperCCD: - Fujifilm's image sensor used in their line of digital cameras. For more information, read their SuperCCD press release.
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.
SVCD Video Parameter Settings
Frame Size: 480x480 (NTSC) or 480x576 (PAL)
Frame Rate: 29.97frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: Variable bit rate up to 2600 kbps
Audio Settings: 32~384 kbps MPEG-1 Layer 2 audio bit rate
SVGA: - SuperVGA refers to an image resolution size of 800 x 600 pixels.
Telephoto: - The focal length that gives you the narrowest angle of coverage, good for bringing distant objects closer.
TFT: - Refers to the type of hi-res colour LCD screen used in digital cameras. TFT = Thin Film Transistor.
Thermal Dye Sublimation - please see Dye Sub
Thumbnail" - A small, low-resolution version of a larger image file that is used for quick identification or speedy editing choices.
TIFF: - Tagged Image File Format - An uncompressed image file format that is lossless and produces no artifacts as is common with other image formats such as JPG.
Time-Lapse: - Capturing a series of images at preset intervals. Also called Interval Recording or Intervalometer.
Transreflective: - This is a type of LCD display that uses ambient light as well as a backlight to illuminate the pixels. Can be seen easier in bright outdoor conditions.
True Colour: - Colour that has a depth of 24-bits per pixel and a total of 16.7 million colours.
TTL: - Through the Lens, used when talking about either an autofocus or auto exposure system that works through the camera's lens. It's also (incorrectly) used to mean SLR, see "SLR" above.
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."
Underexposure: - A picture that appears too dark because insufficient light was delivered to the imaging system. Opposite of overexposure.
USB: - Universal Serial Bus - the data I/O port on most digital cameras 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.
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 colour temperature of the scene. Can be to protect the camera's lens from scratching, fingerprints or dirt.
UXGA: - Refers to an image resolution size of 1600 x 1200 pixels.
VCD - "Video Compact Disc"
A CD-ROM disc that contains video and audio. Typically, a VCD can hold about 74 minutes (650MB) of video and stereo-quality audio. The video and audio are stored in MPEG-1 format and follow certain standards (White Book). VCD video quality is roughly the same as VHS video.
VPS: Video Parameters Settings
Frame Size: 352x240 (NTSC) or 352x288 (PAL)
Frame Rate: 29.97 frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: 1152 kbps
Audio Settings: Stereo, 44.1kHz and 224kbps audio bit rate
VGA: - Refers to an image resolution size of 640 x 480 pixels.
Video Out: - Means the digital camera 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 wide-angle.
White Balance - Refers to adjusting the relative brightness of the red, green and blue components so that the brightest object in the image appears white. See also "AWB"
Wide angle - The focal length that gives you the widest angle of coverage.
X3 Image Sensor - Foveon's new image sensor for digital cameras that captures red, green and blue data at every pixel. Read the X3 press release for full details.
xD-Picture Card - A new flash memory card standard that was co-developed by Fujifilm and Olympus in mid-2002. Rumoured 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.
For more info click here.
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. The most common on digital cameras has a 3:1 ratio (i.e. 35-105mm). See "3x" and "Focal Length"