Our Guide to digital photographic terms:
[A--B] - [C--D] - [E--F] - [G--H] - [I--J] - [K--L] - [M--N]
- [O--P] - [Q--R] - [S--T] - [U--V] - [W--X] - [Y-Z]
Click on the first letter of the name you seek to clarify from the letters above.
ANALOGUE/DIGITAL. Analogue is 'waveform' generated whilst Digital is 'binary code' interface suitable for computer processing. Both Sound and vision is primarily analogue and has to be 'converted'. All digital cameras read the 'analogue' image digitally.
ANGLE OF VIEW: (Zoom lens function) This is dictated solely by the camera lens. If you were to split the lens both left and right, here is a guide to the angle of view you would see: 400mm lens - 6° , 300mm - 8°, 200mm - 12°, 100mm - 24°, 80mm - 30°, 50mm - 46°, 28mm - 74°, 21mm - 90°, 16mm -108°. Note: The normal Human eye is judged at 46° which equates to 50mm lens.
ADOBE RGB - Standard 'professional' implementation CMM colour space.
ANTI-ALIAS - The Video screen technique (algorithm) adopted to 'improve' on screen photographs. (Smoothes the edges to avoid 'jaggies' that can spoil an image on screen). Used by all current computers. over past five years.
AUTO EXPOSURE: Sensors in the camera judge the amount of light automatically which determine the correct exposure. Do not rely on it exclusively though,- be prepared to over ride the settings to suit your subject. i.e. faster time or smaller aperture.
AUTO FOCUS: Press the shutter halfway once to 'set' the focus which senses (infra red beam usually) how far away the subject is. Choose from single central 'auto focus' (AF)or a multi-focus which adopts three or more AF sensors across the entire image.
ASA - Film based ISO rating (now superseded by ISO film speed rating)
'A' SIZES - Part of the European paper sizes A0,A1, A2. A3, A4, A4, A5 .etc.
ASYNCHRONOUS - ability to 'synch' at same time as camera, (as a flashgun)
AWB- Automatic White Balance. Part of your 'built in' camera colour balance ability.
AUTO. - automatically selects and 'optimised' calculation for both 'speed' and 'aperture' and combined with 'auto focus', can be less than ideal for best quality.
APERTURE: The iris through which the light passes. The size of the aperture is important. It is displayed in 'f' stops such as the sequence f/1, f1.4, f/2,f.2.6,f4,f5.6,f8,f/11,f16,f/22 and f32.
ACCESSORY LENS - Add on lenses for 'macro' as in close up and 'telephoto' as in 'far away'.
ARTEFACTS - Over use of the Jpeg format that causes image and colour distortions.
BMP - Bitmap Metafile Photo. Microsoft 'PC' internal image file format (do not use, does not travel well).
BACKLIGHT COMPENSATION: A bright backgrounds often appear too dark. Backlight compensation is required (BLC) which should correct the imbalance of 'auto exposure'.
BIT: The smallest binary digit. Eight bits equal one byte. More bits per pixel equals better screen resolution.
BRACKETING: The black art. Still an essential part of photography which is selecting the same image with varied exposure settings. Not difficult to do and the results are often essential for 'perfect' shots.
BLEACHED OUT FLASH: Flash too strong or too near subject. Incorrect exposure results.
BYTE: One byte of computer storage. One MegaByte is one million bytes.
B&W - the most basic photo now overlooked by most digital Cameras. You can still shoot black and white although the images are automatically 'saved' in standard RGB format.
BLACK POINT COMPENSATION. - important area of ICC profile conversion adoption. Essentially used for RGB to CMYK colour conversions.
BLUETOOTH- The new wireless Camera to computer protocol that enables file transfer, (used by the latest camera phones)
C-41: Standard Colour printing using the Chemical C-41 process. We use the C41 process to develop your (REAL) photographic prints.
CD-ROM. 700 Mb Compact Disk. Media storage for Music, Video and Computers. Widely adopted format for photo storage 'archives'.
CD-ROM DRIVE: Can read the CD format. (CDRW reads and writes to the same format)
CHROMOGENIC: Emulsion film that does not use Silver halide to process (usually black and white) images. (Not a digital process).
COATINGS: The protective layer that protects your lens. It also avoids flare and reflections within the lens itself.
COLOUR CAST: Often resembles a hue of colour due to poor lighting exposure under certain conditions, such as 'strip lighting'. Can also be badly exposed prints.
COMPRESSION: In digital cameras terms this is either LZW for TIFF format images or the the internet friendly Jpeg format. LZW is 'loss less' whilst the Jpeg is 'loosy' in as much that it can devalue an image both in detail and tonally. Use Jpeg with care and use the 'largest' file size that your camera can achieve. Send us TIIF for best resolution or the largest file size Jpeg for best large format prints.
CPU: Computer Processing Unit. The instruction chip built into your computer.
CROPPING: Not all images are used 'full frame'. Often it makes sense to 'crop; unexpected detail from the image to create a better 'composed' and satisfying picture.
CROSS PROCESSING: Unexpected results can be achieved by using the wrong process on the wrong film such as (E6 transparency film) in a C-41 process. At least Digital Photographers do not have that problem!.
CIELAB - Certification International Laboratories Associated Bureau.
CALIBRATION -the process off adjusting your monitor to fixed colour standard. See our easy RGB links.
CRT - Cathode Ray Tube. To you and me a TV monitor (and not an LCD screen)
LCD screen - Liquid Crystal display (backlit usually a flat screen used on laptop PC's.
COLOUR SCALE - Red, Green and Blue ash have a variable 'Grayscale reading' often called 'channels' or 'guns'. 64 bit per channel is 64 grayscale's and multiply this by three (RGB Guns) and you have 64x64x64. Which gives you the (minimum) number of colour capability on your monitor, (or camera).
COLOURSYNC - Macintosh version of ICC colour management
COLOUR RANGE - Not to be confused with COLOUR SCALE. Most Colour printers can only print a limited range of colours. (called a GAMUT)
COMPACT FLASH - Small 'Postage stamp' memory card widely used with options (mb) various capacities.
CMM- Colour Management Module using CIELAB Colour space
CCD - Charge Coupled Device, part off the light sensitive image 'capture'
CMOS - Older style CCD often seen on 'smaller' digital cameras
CF - Type of 'Memory card' used by CANON and many cameras (also XD, SD) acronym
CD - Generic original Laser disc stores typically 640 Mb data (Music, data storage).
DEPTH OF FIELD: This shows how much detail in the immediate background is included in the image. This is usually an Aperture priority situation where the smaller the 'f-stop' the greater the background detail becomes. Hence longer exposure time wise. Can be used to isolate areas of interest from confusing background.
DOUBLE EXPOSURE: A deliberate or mistake that has two images (or more) superimposeed one on top of the other. Unheard of on Digital but common complaint on film cameras.
DOWNLOAD: Transfer of files from one computer to another. Similar to UPLOAD but in reverse! We call our UPLOAD facility SEND images. We hope that is not too confusing!
DPI: Dots per inch. Not that you can actually see the dots on your camera but they are there and called PIXELS as opposed to output resolution which is measured in DPI More dots higher the resolution. See our article on Monitor or Camera resolution for more information.
DVD. The new CD format. (Digital Versatile Disk). A DVD can hold 9 GB of images. Widely used as a Video film format. Only some CD players can read DVD as well as CD's so beware mixing them up.
DX-CODING: The barcode on a pack of DX film/ Determines film speed and sets the camera automatically. DX is not a digital film facility.
DYE SUBLIMATION: Photographic quality method for Digital printing. Uses heat transfer to bind dyes into photographic paper.
DIGITAL ZOOM - Part of an image that is enlarged (interpolated) within the Camera
DOT PITCH - The monitor detail that can be viewed 'on screen' at best resolution. (smaller is better, i.e 0.25 dpi or pixel detail)
DVD - Digital Video Disk. Same as CD but with greater capacity (4.7 Mb Video, data)
DITHERING - Recognised problem with low quality screen monitor image that may lead to 'dithering' of the image to produce an 'approximation' of the closest colour. Most screens can show more than the basic 256 colours, (unless the screen is larger than the video card it is supposed to use).
EXTERNAL FLASH - An option to have an 'extra' Flash' capability.
E-6 PROCESS: Transparency film (Slides) process of the same type used by Cinema film. Sharp and lack of grain is main strength. Transparency film has a long after life and is still widely used for image detail and quality by professional photographers. Storage is also not a problem but cost of processing (for prints) can be. We do not Print E^ film therefore we do not offer this service. Note also that Film formats between Digital and Film differ in size. See our Acrobat pdf for more information.
EXPOSURE COMPENSATION: Available on 'better' digital cameras allowing you to alter exposure one or two 'f-stops as used in 'Bracketing' .
EXPOSURE LATITUDE: How much you can 'overexpose' or 'underexpose' on the (ISO) film speed. Slide (E6) film for example has only a very small latitude for exposure error. Digital Film is more tolerant but can suffer same problems.
FILE and FILM FORMATS: Used for Digital Cameras are mainly TIFF and Jpeg but there are many other image formats available. We can use virtually all Digital Camera Film formats.
FILM SPEED: (International Standards Organisation. Determines Film speed. Measured film speeds are (ISO 25-64 Slow), (ISO 100-200 Medium), (ISO 400 Fast), (ISO 800+ Very fast).
FIXED LENS: As that used by Mobile camera Phones and the smaller type of Digital Cameras. Fixed lens, fixed aperture (f-stop), and possibly auto exposure. Advantages of light weight and portability are sometimes more important.
FLARE: Stray light in the lens. Can be distracting or rather nice is artistically done!
FLASH MODES: Built in flash unit with auto flash capability. Syncs with the camera for exposure automatically. Use with care.
FOCUS LOCK: Enabled it allows you to 'fix' the 'auto focus' on the sensor and shoot at another identical or similar image. Just press the shutter button half way should do it.
FOCUSSING: The art of composing an image where you want it to be sharp. Auto focus will work of course, just do not expect it to deliver astonishing results all the time.
FOGGING: Discolouration or unwanted light on the film image. A film camera problems but can be replicated on Digital image on computer, for those (retro photographers) wishing to do it.
F -STOP - often used to 'enlarge' or 'reduce' aperture within Camera (affects focus)
FLARE - Often caused by ''close proximity' to light source or bright light reflection.
FLASH UNIT - Read Flash gun, usually portable accessory to a Camera.
FLASHPIX - Kodak idea of enable 'multi resolution' images on a Kodak CD for example. Requires Kodak 'plug-in' to view images.
GAMMA CORRECTION - ranges from 1.4 (macintosh) to 2.2 (PC's). Images from one platform may look 'darker' or 'brighter' on another. There is no 'Gamma standard'.
GIF: (Graphic Interchange format) Don't use it, even at half price. It's a web logo format and not a digital image format. Jpeg is better.
GIGABYTE: 1024 MegaBytes of (hard disk), Media storage.
GRAIN: The 'texture of the actual film grain' showing through due to over expansion of the image or wrong film speed used. Larger the grain appears the less sharp the image.
GUIDE NUMBER: Flash gun indication for power output of the flash unit. Based around ISO 100 film speed (in metres).
GRAYSCALE - The number of 'graduations in a black and white image. Can be x16, x32, and 64 etc. See Colour scale.
GAMUT - Colours can be 'out-of-Gamut' when the number of colours exceed the limitations of the Printer. Also the human eye can only see a 'limited' number of colours in the colour rainbow (spectrum)!
GENERIC - The same type as commonly used by another type of printer or device. (Be wary all Digital cameras are 'generic, but are not universally compatible)!!
HARD DISK: Storage devices for computers are all digital and are either (a) RAM volatile storage (b) EPROM style storage as in 'Media Cards' seem volatile storage (c) spinning platen disk (called hard disk) storage. All have their odd limits and uses and occasionally do fail (and it can be sudden). Make frequent back ups (or use off-line storage) as soon as you are able. On this site We offer an online storage service to 'free up' your camera memory in minutes.
HIGH RESOLUTION: Megapixel camera of at least One Megabyte. Hoever most images 'by default' are a lot less than full resolution.
HIGHLIGHT- The brightest part of an image. Not to bee confused with 'flare'
HANDHELD - Lightweight Camera device that relies on a fixed length of time to take the image. Wide aperture reduces 'time', smaller 'aperture requires more 'time'. Can be an 'AUTO' setting. Always use a steady hand in case of Camera shake
HOT SPOT: Flash gun or solar flare that causes an unwelcome reflection in the image.
ICC- International Colour Consortium. responsible for colour consistency across devices used for 'colour management'.
ICM - Windows PC version of the ICC colour management using CIELAB
IMAGE MANIPULATION; Altering an image using Digital means. We do this on site automatically.
INFINITY LOCK: Auto focus often has problems focussing through glass. You can set 'Infinity' to focus outside the glass plane.
INFORMATION EXCHANGE: (IX) APS film format terms on a magnetic strip (labs make use of this information to batch process your prints). These include (1) Date and Time (2) MRC Mid roll change , (3) Print format selection, (4) PQI Print quality improvement, (5) Print quantity, (6) Print titling.
INK JET PRINTER: Often used for inferior digital photographic prints. Incredibly slow, expensive to maintain, prone to calibration or ink problems. Impress your grandmother, maybe.
INTERPOLATION: A software solution used by Scanner Manufacturers (to artificially boost resolution) and used by PhotoShop when using the 'bicubic' method of scaling an image to a large (or smaller) size. Not ideal for enlarging images. On this site we use a much better method to size images that keep all the detail intact without loss.
INTERVALOMETER: Time lapse photography term for images taken at regular intervals from mins to hours long.
ISO: International Standards Organisation. Determines Film speed. Replaces the past ASA and DIN speed ratings used for film speed.
IMAGE QUALITY - Not to be confused with 'resolution'. Even higher pixel camera can have 'bad quality images'. Quality refers to overall focus, colour balance and detail enhancement.
INDEXED COLOUR - Not generally used for Photographs as reduces arrange of colours to a very low standard such as that used by GIFS (used in web display browsers).
IEEE 1394 - Commonly called 'Firewire' can be used to transfer Images (Like USB) from one device to another - but a lot faster. Becoming an option on the more expensive SLR type cameras and most VIDEO cameras Standard on Macintosh computers.
IMAGE OPTIMISATION - This usually means that it should be the correct 'resolution' for the device to which it should be printed on and colour balanced to suit a 'target'. PPD file (Paged Printer definition).
INFRA-RED -Earlier Camera to computer wireless connection device, often used by PDA's (or handled computes)
JPEG- Joint Photographic Experts Group. various versions. Currently Jpeg 2000. Improved 'compression' capable of 158:1 compression without visible loss off image. Widely used Camera format. Can suffer from over use and over compression. (see Artefacts)
JOULES - Part of the 'Kilo Joules' energy measurement often describing power of a flash unit.
KELVIN - White point temperature that affects perceptual colour. i.e. 9300 degrees Kelvin. (also 5000, 6500 degree. (7500 degree 'K' is used in Video production). Also called D50 for 5000 degree and D65 for 6500 degee temperature (monitor) ratings.
LENS - biggest single factor affecting 'resolution'. Used to focus image in Camera
LCD Monitor: The term used to display camera images on the back of the camera. Can be used for checking focus and Preview of past shot images. Camera functions are all displayed on the built in screen.
LOW RESOLUTION: Anything that is used on the internet to preview images.
LED: Light Emitting Diode. A warning lamp found on the front (usually) of the camera to indicate some operation, such as a 'self-timer'.
LPI - (Lpi) Thet term used by colour printers to determin the 'screen ruling' to be used in printing. Not to be confused with 'DPI' term also used in printing resolution. LPI stands for 'Lines per inch'.
LZW - A compression algorithm commonly used to compress TIFF files (as opposed to jPeg) that offers good file compression (on larger photo file sizes) without loss of colour integrity. Tiff files can be saved using 'LZW file compression (an option inPhotoShop)..
MAXIMUM APERTURE: Wide open aperture for the lens. i.e. You would need this for low light conditions.
MEGAPIXEL: A million pixels. This is the bottom end for most Digital cameras but also the top end for most mobile camera phones.
METERING PATTERNS: Exposure metering system. i.e. spot metering centre, (most accurate), Multi-zone (second best) or centre weighted pattern 'averaging' with emphasise on centre is the usual choice.
MODEM: The analogue signal to digital converter used by laptops and most computers connected to internet that do have 'broadband' capability. Often recent computers have both options 'built -in'. You can use both to use our site services. Dial up 'modem' is just a bit slower than broadband. 56Kb against 128kb for base ot (UK) broadband connection. Our site speeds up connection by x25 times.
MORPHING: The term used to change one image (by animation) a number of images into another.
MOTOR WIND: Motor film advance mechanism. Also rewind the film. Another thing we Digital users do not have to worry about.
MEGABYTE - 1 million bytes (1 Mb =Megabyte) Hard disk size usually (or is is 1024 bytes exactly?)
MEGA PIXEL- 1 million pixels (image capture on camera light sensitivity)
MACRO - Often an option on mid range cameras, being able to use the 'built in' zoom len to focus on small objects near to lens. Not as good as a 'Microscope'! Can be a 'stand alone' lens option on some High end digital cameras.
MID TONES - clearly defined areas of grey to colour between the dark and 'highlight' areas.
NEGATIVE FILM: Reversal film required for c-41 process prints, (from transprencies) . Not required for Digital cameras, (another cost saving).
NOISE - Can occur with low light situations. Shows as random 'colour flecks' in shadows.
NUBUS BOARD - Supplementary computer 'card' Interface that was available for earlier Digital 'SLR' cameras such as the Canon RC-560. High End solution. (now redundant)
OUT-OF-FOCUS: Usually caused by (1) Autofocus not set correctly (2) Fixed lens, subject to close to camera
OPTICAL ZOOM - Part of an image enlarged by the lens of the Camera 'zoom - lens'
PANTONE - Industry standard 'flat colour' specification system (not unique). Used throughout Commercial Litho printing (not photo printing).
PARALLAX: Useful but potentially inaccurate way to view images thought the 'parallel' small glass (eye glass) screen on the camera. This problem does not occur on SLR type cameras.
PIXEL: The smallest element of your digital image making up the picture.
PIXELLATED: Vast enlargement causes pixellation of individual image 'pixels'.
PHOTO CD: Kodak system offering three different resolution on a CD.
See our Camera Resolution page for more information.
PRINTER: The print device you can proof or print your image with varying degrees of detail according to resolution or capability.
PPD - Page printer description. The instruction by which your 'printer interprets your image. Every printer made has a unique PPD, Some are just 'generic'
PIXILLATION -whereby the image 'resolution' has been enlarged beyond acceptability (causing the individual pixels to be visible)
PDF - A portable Document format widely used in Publishing. It can combine Photographs add Texts as a 'self contained' page. Digital images can be 'saved' in PDF format but are not directly supported in the Camera.
PCMCIA- external laptop type 'Media card' storage or modem device
PNG - Portable Network Graphics. Similar to Jpeg but with GIF capabilities. More of a web picture format.
PLASMA screen -A relatively expensive option for large screen VIdeo and TV.
PICT -Picture PICT. Macintosh internal image file format (do not use).
PHOTO PRINTS - digital using 'Photographic' on Photographic paper using the RGB process. There are a multitude of alternatives, (not all print worthy)
RAM: Volatile memory used by computers for fast (but temporary) storage. Your memory card is not RAM but it is similar it that it can also hold a memory (but for a longer term indefinately).
RED EYE: Not that we can correct this problem for you. Much better still to avoid it altogether and use another image by 'Bracketing' your exposure.
RESOLUTION: Sharpness and Detail. We have donated an entire page or two on this very subject. Click either and be informed!
RGB - Red Green and Blue, The standard by which all monitors agree to create the most visible range of colours on screen.
RESOLUTION - refers to (much abused) size of Pixel image captured by camera. See our article on Monitor resolution. (link)
RENDERING INTENTS - Part of the colour management system 'colour mapping' of the ICC definition such as: absolute calorimetric, relative calorimetric, perceptual and saturation.
SATURATION - Overall colour balance. i.e. from bright colours to softer hues.
SCANNER: Can be 'flat bed' or 'DRUM' type (for high end scanning). Scans prints and transparencies. Various chosen resolutions and an acquired skill to get correct colour scans at best quality.
SCSI: I(Small Computer Serial Interface) Industrial strength computer connection. Fast but can be temperamental. Superseded by FireWire and USB connections which are both cheaper and easier to use.
SELF-TIMER: Delayed picture taking for self portraits.
SLR: Single Lens Reflex. Preview image is through the actual lens, so you can see the complete image before you take the picture. Only the latest Digital Camera have SLR capability, and cost a premium.
SLOW SYNC: Enables (if it is set) a better exposure than simply Flash on its own. Allows a much better exposure of subject with background detail. Requires a very steady hand held camera (or tripod).
SINGLE-USE CAMERA: I don't think we have seen the last of these tacky monsters. Expect a digital version soon!
SHARP - refers to overall 'focus' not to resolution. (contributory factor)
SD - Type of 'Memory card' used in many cameras (also XD, CF) acronym
SHAKE - Age old problem of camera shake. Many remedies available but nothing to do with your camera. See 'handheld'.
SEPIA - Brown and white simulation for a ''Victorian' look to photographs. Can be re-created on some cameras using standard options on your camera and printed using normal photo print process. Alternatively we may offer this as an option in the future on our web site at photo site at www.photodigitalenhance.com. (Not to be confused with 'true' black and white Photography using Silver halide prints only available to film cameras).
SMART FLASH - Memory 'credit card' sized type media card for digital cameras.
SLR - Single Lens Reflex. Superior image previews through the 'camera lens'.
sRGB - Windows version of Adobe RGB for Calibration profiling of images on PC.
S-video - usually a MUCH better preview option (than VGA) for TV screen.
SHARPEN - generally meaning to improve focus but specifically to 'heighten' pixel edge by contrast technique (used in PhotoShop)..
SHADOWS - the darker parts overall of an image.
THUMBNAIL: The smallest image that you can see on your camera back of the camera. Also some software automatically generates a 'Thumbnail' for you to see a small preview on screen. We convert your pictures to THUMBNAILS automatically when you use our 'Simply STORE images' page featured.
TIFF: Tagged Image File format. Oldest and still the best image file format that offers true (but large) imaging files. It is often 'compressed' easily and can be converted to 'jpeg' with some loss of quality.
TELEPHOTO- A 'stand alone' Lens that can replace the standard lens on most mid range to high digital cameras. Enables good 'close up' detail with professional results.
USB - Ubiquitous USB. Not fast, but a very convenient cable solution to 'link up' computer devices such as 'Printers, Cameras and Modems etc.
VIEWFINDER: That small window on top of the camera sometimes indicates exposure detail or focus. It has some parallax error close up i.e. cannot show the entire image, but it is easy to use. SLR camera do not suffer from this problem.
VRAM: A kind of RAM enabling the computer screen to display more colours.
VARIABLE ZOOM- part of the Camera focusing system. There are three types. (1) DIGITAL ZOOM, (2) Camera lens zoom. and a combination of the two types often used on 'mid range' cameras. Camera Lends zoom yields most detail, (although you will not see any difference through the tiny Camera 'preview' screen.
WHITE POINT COMPENSATION - At which point the three RGB colour produce pure white intensity, (usually pre-set by Monitor manufacturer but can 'slide' over time and may need readjustment after six months).
XD - Type of 'Memory card' used in many cameras (also CF, SD) acronym.
ZOOM: A cross between a 'Telephoto' and a range of 'fixes focal length lenses' (add on accessories) Digital Camera do not have such a great choice of lenses (but this is changing fast). There are two types of ZOOM for most digital cameras (mid price range cameras). (1) Digital zoom - inferior (interpolation) enlargement. (2) Lens zoom - superior lens mechanism to enlarge images. (3) Mixture of both.
This list is in the process of being updated soon - but contributions are welcome.
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