THE VISIBLE DIFFERENCE A-Z OF DIGITAL PHOTOGRAPHY THE A TO Z OF DIGITAL PHOTOGRAPHY A Algorithm A set of processing or working instructions that, because of their high preci- AC adapter Mains adapter. sion, can be carried out independently Enables the connection of the digital by a mechanical or electronic device. camera to the mains electricity supply. Algorithms are, for example, the set rules for addition and subtraction etc. ADC Analog-Digital Converter. However, they are also the instructions Hardware that converts analog informathat are established in a programming tion into digital data. (� AD-Conversion) language. Algorithms simply allow the computer to solve particular problems. AD conversion Analog-Digital conversion. In image editing, algorithms are used to In order to process an � analog signal alter images, e.g. 3 D Cubic Algorithm. (e.g. a photo) in a computer, it must first (� TruePic) be digitised (converted into a specific mathematical format of binary code). Aliasing Pixel-shaped curves on the diagonal Pictures are usually digitised with the edges of objects. This can sometimes help of a digital camera or a scanner. occur since all graphics consist of individual � pixels. Anti-aliasing reduces Additive colour Describes a colour system that is based this unwelcome effect by recalculating mixing upon the addition of the three additive the contrast values of the neighbouring primary colours (red, green, and blue). pixels and matching them up with each For example, colour televisions and comother. puter monitor displays use the principle of additive colour mixing. Altavista Well-known � search engine in the � internet. Add-on / � Extension to a program such as Excel Add-in or Word that increases the available Analog Opposite of � digital. functions. These add-ons/add-ins are Analog data merges continuously into developed and distributed by the respeceach other without clearly defined steps tive software company or other firms. (e.g. the colours of a rainbow are AE Automatic exposure. not obviously separable from one another). A-Z 2 3 THE A TO Z OF DIGITAL PHOTOGRAPHY Aperture Mechanism behind the lens that controls ever, not for umlauts) enables the corthe amount of light entering the camera. rect data transfer between software and The aperture not only influences picture hardware. The ASCII-code employs the brightness but also regulates � depth of first seven � bits of a � byte. The first focus. Most cameras are equipped with 32 symbols are used as control syman iris aperture that can be freely adbols, e.g. to control a printer. justed or set according to pre-selected values. ATA AT Attachment. � Interface for � hard drives. AppleTalk A network protocol used by Macintosh computers. ATA-Flash-Space-saving integrated � plug-in Cards memory cards. APS Advanced Photo System. Developed together by five companies, this film Autofocus (AF) Automatic focus adjustment. There are system is distinguished by simple operabasically two main AF methods: the tion, a new picture format (16 x 30 mm) focus detecting method, or passive auto as well as a choice of three picture forfocus usually employs a CCD and mats. Additional information (such as works by evaluating the amount of conexposure, aperture and date) can be trast or the phase difference in a scene. recorded on the magnetic strip of the Distance metering or active autofocus APS film. However, APS is not digital utilises an (infrared) light emitter and rephotography. ceiver in a triangular surveying system. Alternatively, the camera uses ultra- Aqua Case Waterproof plastic casing for sound (sonar) and measures the time � OLYMPUS � CAMEDIA digital taken for the sound signal to return. cameras. This data is converted by a microprocessor into information about distance ASCII American Standard Code for Information and thereby enables the automatic Interchange. focusing of the lens. The commonly used � binary code for a total of 128 symbols (letters, numbers, punctuation and special symbols, how-A-Z 4 5 THE A TO Z OF DIGITAL PHOTOGRAPHY Average A special � exposure metering technique Bitmap A representational form for a digital metering that measures the average light intensity image in which each � bit in the comacross the entire frame. puter's memory corresponds to one � dot on the screen or printer. Blooming The opposite of � noise; an image error B that has been more or less eradicated in the newer digital cameras. It describes Baud A unit of measurement for data transthe "overflow" of electrical charges mission rates, named after the French between the individual sensors on a engineer, Baudot. � CCD element. Binary This is the name given to the representa-Bluebox A process known from television and tion system of numbers consisting solely movie productions. Actors stand in front of the figures 0 and 1. Just like the tenof a coloured wall, usually painted blue. figure decimal system (0-9), in the binary Later, a different background is put in system, larger numbers are made up by for the blue areas on the recorded combining the numbers 0 and 1. image, giving the impression that the actors are e.g. on top of a mountain, Bios Stands for Basic Input / Output System although they never left the studio. and describes the basic program of a computer. bps � Bits per second. Refers to the number of bits transferred in one second. Bit Binary digit. The smallest � digital unit The bps notation is often found on that can show only two states 0 or 1. � modems and � serial interfaces. 8 bits produce one � byte. Browser Describes a program used to display Bit-depth � Colour depth. information, especially on the � internet. Bug Describes a programming error. This can be removed by correction or rewriting the program codes. A-Z (� Patch) 6 7 THE A TO Z OF DIGITAL PHOTOGRAPHY Bug-Fix Removing a software error by means of a Candela Unit of illumination (cd). 1 cd is 1/683W small additional program. per steradian. Byte � Binary data packet made up of 8 CCD Charge-Coupled Device. � bits. A byte can represent values bet-A light sensitive semiconductor that ween 0 and 255. It can depict 256 symconverts received light into voltage bols, numbers or colours. In the compuaccording to the level of brightness. It is ter field, larger byte size is described used as a � chip or line sensor in digital using the prefix letter for the abbreviation cameras and � scanners. (� progressive of the exponent of 2. Therefore: CCD, � video CCD) 1 Kilobyte = 1 KB = 1,024 bytes 1 Megabyte = 1 MB = 1,048,576 bytes CD-ROM Compact-Disc-Read-Only-Memory. A 1 Gigabyte = 1 GB = 1,073,741,824 "read only" CD-ROM can hold up to bytes approximately 700 MB of programs, 1 Terabyte = 1 TB = 1,099,511,627,776 pictures, text, or other data. bytes. Centre-weigh-This method of � exposure metering is ted average often used for subjects with an even C metering contrast distribution. (� Digital ESP (selective multi zone metering); Calendar card � SmartMedia-function card. � reflected-light metering; � light metering, � spot metering) Calibration The reciprocal balancing or tuning of input and output devices, in order to re-Charger Battery-charger. ceive a matching value. In this way, the colours on a monitor can be matched Chip General description for � integrated cirwith the printer's colours. (� colour mancuits whose components (e.g. transisagement) tors, diodes, resistors) are mounted on a small plate of the semiconducting CAMEDIA The name given to the � OLYMPUS material silicon. Digital Imaging products. A-Z 8 9 THE A TO Z OF DIGITAL PHOTOGRAPHY CIE Commission Internationale de l�Eclairage. Colour The calibration of all peripheral devices An international standard commission for management that feature in the production of colour colour metric measurements. The set images (monitors, scanners, colour prinstandards are the basis for the colour ters etc.). For example, by using a definition in � DTP standards. colour management system, the data from a scanner is converted into values CISC Complex Instruction Set Computer. A for a standard colour range. The data is type of � processor that recognises and then arranged so that the printer can processes a large number of complex produce good colour prints. and powerful instructions without the need for additional software. Colour noise The incorrect reproduction of colour on an image (e.g. dots on an area which is CMYK Cyan, Magenta, Yellow, and Key/Black. supposed to be pure white). (� Noise) These are the printer colours used to create colour prints. (� subtractive colour Colour Describes the spectral energy distribumixing) temperature tion and thereby the colour quality of a light source. The temperature of a Colour depth This refers to the maximum number of colour is given in � Kelvin (K). It is colours that can be recorded by digital important to choose the correct tempecameras and scanners or can be disrature so that a subject can be photoplayed by graphics cards. A true colour graphed in its true colours. The specrepresentation can be achieved at a trum that can be seen by the human colour depth of 8 bits per primary colour, eye lies between approx. 2,790 K and that is a 24 bit colour depth. In this case, 11,000 K. The international norm for 256 bits are available for one pixel. With average sunlight is 5,500 K. an RGB signal, this value is then multiplied by a factor of three so that a total of Compact Smaller dimensions and reduced weight 256 x 256 x 256 = 16,777,216 colours digital camera make these easy to handle models ideal can be displayed. High-end scanners, for travel and everyday use....
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