HowTo

Help and How-Tos - Glossary of Terms

February 2005

An increase in the popularity of digital cameras and the introduction of digital minilabs has contributed to rapid changes in technology. As an aid to our customers, we've researched a list of common terms you may encounter. If you are wondering about a term not found here, let us know, and we'll try and add it!

APS (Advanced Photo System)

APS is a relatively new film format that permits more compact, easy to use, light weight cameras. APS cameras use filmcartridges that are easy-loading (i.e. leaderless cartridges). Compared to 35mm film, this system was designed to be easy to use and handle, since the negatives are always stored safely in the film cannister. APS films also have a magnetic coating on which the camera can encode, among other data, the number and size of desired reprints.

While these cameras were popular a few years ago, they are now (like any film camera) gradually fading away in favor of digital cameras.

Bit

Smallest unit of memory in a digital system. A contraction of "binary" and "digit." A bit is either on (1) or off (0).
See also Byte, Kilobyte, Megabyte, Gigabyte, Megabit

Byte

A group of 8 bits. It’s the basic unit of information used by a computer. A single byte can represent one of 256 values (A number between 0 and 255).
See also Bit, Kilobyte, Megabyte, Gigabyte

C-41

Standard chemical process for developing colour negative film.

CCD

Most digital cameras record an image on a Charge Coupled Device (CCD) - a chip containing a grid-like field of extremely small, light-sensitive cells (photodiodes or photosites), each of which emits an electrical signal in proportion to the intensity of the light striking it.

Charge Coupled Devices have been used for used in a variety of camera equipment including Camcorders.

CF (Compact Flash)

Compact Flash cards were introduced in 1994 as a removable memory card and are about the size of a matchbook. CF cards have a 50 pin connector, and are built using a similar set of specifications as PC Cards, making it possible to easily insert compact flash cards into a PC Card slot with the correct adapter. Compact flash cards are typically available in capacities up to 4 gigabytes. The latest CompactFlash card specification (version 2.1) supports data rates up to 16MB/sec and capacities up to 137GB.

Compact Flash cards are also available as Microdrives, a small compact hard drive technology. CF cards are still in popular use today with digital cameras.
See also: PC Card, Sony Memory Stick, SmartMedia, SD Cards, MMC Cards, xD Picture Card

Colour Depth

Refers to the colour resolution of an image. A higher colour depth means that an image can represent a wider range of colours, but will require more memory to store. Typical colour depths are 1 (Black and White), 8 (Used by GIF images), 16 and 24 (Photographic quality).

See also RGB, TIFF, GIF

CMOS Sensor

Complementary Metal Oxide Semiconductor (CMOS) Sensors are an alternative sensor used in some low end digital cameras, in place of CCD sensors. CMOS sensors tend to be more prone to noise than CCD sensors, and are less sensitive to light. However, they have the advantage of being cheaper and easier to manufacture and consume less power than a CCD sensor.

CMYK (Cyan, Magenta, Yellow, blacK)

The four-colour system that many printing devices use to reproduce colour. Typically, this system is used by commercial printers and inkjet printers.

This colour system uses four channels, one for Cyan, Magenta, Yellow and blacK. As an example, in a digital image that has a colour depth of 32 bits, 8 bits (one byte) is reserved for each colour channel. (8x4 = 32).
See also: RGB, Colour Depth, Byte

CRT (Cathode Ray Tube)

A device used to display an image on a phosphor covered glass screen. Electronic television is based on the development of the cathode ray tube (CRT for short), which is the picture tube found in modern television sets. A CRT is a specialized vacuum tube in which images are produced when an electron beam strikes the phosphor coated surface inside the tube. TVs, computers, automated teller machines, monitors and radar displays all contain cathode-ray tubes. Phosphor screens using multiple beams of electrons have allowed CRTs to display millions of colours.

CRT displays are rapidly being replaced by newer display technologies such as LCD, OLED and Plasma screens.
See also: LCD, OLED, DPI

DPI (Dots Per Inch)

Dots per inch. A way of measuring output image resolution. As it's name implies, image detail is defined by calculating the number of pixels defined across one inch. A higher DPI value indicates that there are more dots in a single inch. Typical image resolutions include 72 or 96 DPI for computer screens, and 300, 600, 720 and 1440 DPI for most printers, and 300 DPI for photofinishing systems.

Higher resolution images generally produce a sharper, more detailed image. However, other factors can also come into play (such as imaging technology) that also strongly affect image quality, since an image produced at 300 DPI on a photofinishing system can look better than an image printed at 1440 DPI on an inkjet printer.

When printing an image, DPI in itself doesn't mean anything; this information needs to be combined with image dimensions before an image can be produced on a output device (such as a printer, or a computer monitor).
See also: PPI

E-6

Standard chemical process for developing Ektachrome-compatible slide films.

ExpressCard

Introduced in 2003, it's a new standard developed by the PCMCIA standards organization that is designed to eventually replace the PCCard technology. This new card technology is based on the PCI Express and USB 2.0 standards. Designed to be smaller and cheaper, this technology will eventually replace PCCard technology on most laptop and mobile computer systems.
See also: PCCard

Firewire (IEEE 1394)

FireWire is a cross-platform, high speed serial data bus that can move large amounts of data between computers and peripheral devices. Invented at Apple, FireWire enables the connection of new digital consumer products - including digital camcorders, digital video disks, set-top boxes, and music systems - directly to the personal computer. It features simplified cabling, hot swapping and transfer speeds up to 400 megabits per second. Major manufacturers of multimedia devices are already adopting the FireWire technology. The IEEE1394b standard is an updated standard which features transfer rates up to 800 megabites per second.
See also: USB, Megabits

Film Speed (ISO number)

An indication of the film's sensitivity to light, and therefore its ability to take pictures under different lighting conditions. Higher ISO numbers means that film is more sensitive to light, allowing you to take pictures in low lighting conditions, although often resulting in granier looking images. Conversely, lower ISO number resulting in film that is less sensitive to light, but can produce better quality pictures. These concepts similarly apply to digital cameras. ISO numbers were previously referred to as ASA numbers.

Flash Memory

A type of computer memory that does not require an external power source to retain it's data. Sometimes referred to as solid state memory. Common examples include the memory cards used in digital cameras, Portable MP3 players, PDA (Personal Digital Assistants) and some cell phones.
See also: Smartmedia Cards, xD Picture Cards, Compact Flash Cards, PC Cards, Sony Memory Stick and SD Picture Cards.

F-Number

A number that expresses a lens’ light-transmitting ability - i.e. the size of the lens opening. Usually found on the barrel of a lens, f-numbers indicate the size of the aperture in relation to the focal length of the lens. A smaller number indicates a larger lens diameter. ƒ/1.4 signifies that the focal length of the lens is 1.4 times as great as the diameter. All lenses set at the same f-number transmit the same amount of light.

GIF

A acronym for Graphic Interchange Format. GIF is a graphics file format commonly used to display simple graphics on a web page. This format uses LZW compression and supports no more than 256 colours (8 bit colour) in a single image, and as such, is unsuitable for accurately representing photographic images.
See also: JPEG, Colour Depth, Lossless Compression.

GigaByte

1,073,741,824 Bytes or 1024 Megabytes. A unit of measurement for data storage capacity. A gigabyte is roughly equivalent to just over a billion bytes.

For marketing reasons, hard drive manufacturers often erroneously state the capacities of their data storage products with the assertion that one gigabyte = 1,000,000,000 bytes instead of 1,073,741,824 bytes. The result is that the storage capacity that they advertise is inflated.

As an example, a manufacturer may sell a hard drive that has a capacity of 80,048,357,376 bytes and thus advertise it as a 80 Gigabyte hard drive. In order to arrive at the correct capacity, divide 80,048,357,376 bytes by 1,073,741,824 to arrive at the actual capacity of 74.55 Gigabytes.
See also: Byte, Kilobyte, Megabyte

JPEG (Joint Photographic Experts Group)

A very popular image format. JPEG is a lossy compression format that is well suited for photographic images; in part due to the popularity of the World Wide Web and the excellent compression ratios that can be achieved.

JPEG is supported by virtually any piece of software today that deals with digital images. This format is commonly used on web pages and is supported by many types of hardware including digital cameras, PDAs and digital imaging systems.
See also: GIF, TIFF, Lossy Compression, Lossless Compression

Kilobyte (KB)

1024 bytes. A kilobyte is a unit of measurement for computer data storage. A kilobyte is 1024 instead of 1000 bytes because computers only work with binary numbers and 2 to the power of 10 (2^10) = 1024. Since 1024 is close to 1000, the computer industry felt years ago that it would be appropriate to refer to this conveniently as a Kilobyte.
See also: Bit, Byte, Megabyte, Gigabyte

LCD (Liquid Crystal Display)

A popular display technology, now commonly used in flat computer screen displays. LCD displays require a backlight in order to function, since they do not emit light themselves. Such displays function by preventing light from being emitted through a thin film to produce an image.

LCD displays have been in use for many years, primarily in small electronic devices such as electronic wristband watches, calculators and electronic thermostats panels. Recently, colour LCD screens have become popular due to reduced costs and improved manufacturing techniques.
See also: OLED, CRT

Lossy Compression

Refers to a method to reduce the size of digital media files so that it consumes less space on a storage device. This is achieved at the expense of quality. Minute details that are usually not visible or audible to a human are discarded to significantly reduce the media file's storage requirements. Common examples of media files that use lossy compression techniques include JPEG images, MP3 Audio, Ogg Vorbis Audio and MPEG 2 Video (Used in DVDs).
See also: JPEG

Lossless Compression

Refers to a method to reduce the size of digital media files (or computer data) so that it consumes less space on a storage device. This results in more efficient storage. Unlike lossy compression, lossless compression perfectly preserves all details, so that when the data is decompressed for playback, the original data is restored without alteration. Examples of lossless compression algorithms include ZIP, LZW and Huffman. These and many other compression algorithms are used inside of formats such as TIFF (ZIP, Huffman), GIF (LZW) and PNG images.
See also: TIFF, GIF

Medium Format

Also referred to as 120/220, this is a 6 cm wide film format typically used by professional photographers. Negatives or slides are typically 6x4.5, 6x6, 6x7, 6x8 and 6x9 cm in size.

Megabit

Short for a million bits. Usually used to describe how fast data can be transferred in a data communications standard. Sometimes used to refer to storage capacity.
See also: Bit, Byte, Kilobyte, Megabyte

Megabyte

1,048,576 Bytes or 1024 Kilobytes. A unit of measurement for data storage capacity.

For marketing reasons, disk drive manufacturers often erroneously state the capacities of their data storage products with the assertion that one megabyte = 1,000,000 bytes instead of 1,048,576 bytes. The result is that the storage capacity that they advertise is inflated.

For example, a 250 Megabyte ZIP disk really only has a capacity of 238 Megabytes, or 250,331,136 bytes.
See also: Byte, Kilobyte, Gigabyte

MegaPixel

A million pixels. Normally used to describe the level of detail that can be obtained from the CCD sensor in a digital camera. For example, a 5 megapixel camera can produce an image that contains approximately 5 million pixels, usually arranged in a grid 2592 pixels wide X 1944 pixels high. (2592 x 1944 = 5,038,848).
See also: Pixel

MMC (MultimediaCard)

MultiMediaCards are one of the smallest flash cards available (xD Picture Cards are slightly smaller), about the size of a postage stamp. They were introduced in 1997 and initially used in the mobile phone and pager markets. Today, they are commonly used in digital cameras, mobile phones, and MP3 players. The MultiMediaCard Association sets the specifications for MMC.
See also: xD Picture Card, SD Card, Smartmedia Card, Compact Flash Card

NiCad or NiCd (Nickel Cadmium)

A type of rechargeable battery technology. Nickel Cadmium (NiCad for short) batteries have been used for more than 50 years and are still common on the market today. Such batteries are an economical alternative to buying disposible batteries since they can be recharged hundreds of times under normal conditions.

NiCad battery performance is not adversely affected when overcharged. However, there are some drawbacks with this technology. This includes the fact that Cadmium is toxic, they tend to develop a "memory" and will gradually discharge over time, making them unsuitable for some standby applications.
See also: NiMH

NiMH (Nickel Metal-Hydride)

A type of rechargeable battery technology. Nickel Metal-Hydride (NiMH for short) batteries have become popular in the market recently and are slowly replacing NiCad batteries. The major advantages of this battery technology is the elimination of toxic cadmium elements. These batteries can also store 40% more energy than NiCad and do not suffer from "memory" problems.
See also: NiCad

OLED (Organic Light Emitting Diode)

An OLED is an electronic device made by placing a series of organic thin films between two conductors. When used to produce displays, OLED technology produces self-luminous displays that do not require backlighting (as opposed to LCDs) resulting in thin, compact displays. The display layer can be as thin as 500 nm (0.5 thousandths of a millimeter).

OLED displays have the potential to replace LCD displays in the market. They can already be seen in a limited number of digital cameras, cell phones and PDAs. They have a number of advantages including:

Wide viewing angle
Lower power consumption.
Increased brightness
Faster response time for full motion video
Broader operating temperature ranges
The potential for reduced manufacturing costs

A standard allowing a variety of devices to plug into and expand a computer system or other electronic device. PC Card slots are almost universally found on all laptop computers, and can also be found on a number of handheld devices. There are three different cards types, referred to as Type I, II and III. Each card type is sucessively thicker than it's predecessor. All cards are 85.6 mm long and 54.0 mm wide and 3.3 mm, 5.0 mm or 10.5 mm thick.

PC Cards are simply plugged into the host device to provide additional functionality. Common types of PC Cards include memory cards, Networking, Hard Drives, Dial up modems, SCSI and CD-ROM drive interfaces. The only types of PC Cards used in the photo finishing industry, however, are typically memory cards or Microdrives (small compact hard drives). Compact flash cards are built using a similar set of specifications as PC Cards, making it possible to easily insert a compact flash card into a PC Card slot with the correct adapter.

This standard will eventually be replaced by ExpressCard technology.
See also: Compact Flash Card, MMC, SD Card, Smartmedia Card, xD Picture Card, ExpressCard

PIXEL (Picture Element)

Represents one element in a digital image. Pixels in a digital image are arranged in a grid with each pixel representing a colour at a specific location in a digital image. The more pixels you have, the more detail an image represents.
See also: DPI, PPI, Resolution

PPI (Points Per Inch)

A way of measuring input image resolution. As it's name implies, image detail is defined by calculating the number of pixels defined across one inch. Higher values indicate that the pixels are smaller, due to more pixels in a single inch. Higher values also generally result in a more detailed image.
See also DPI, Resolution

Resolution

The number of dots or pixels contained in a given area. Image resolution is used to describe the density of the pixels (or dots) in an image. The higher the resolution, the more detail you have, resulting in a sharper image.
See also: PPI, DPI.

RGB (Red, Green, Blue)

A method for describing colour numerically in an image. By combining varying intensities of red, green and blue together, any colour can be represented. For example, a pixel in an image that contains 100% red, 0% green and 100% blue would produce a magenta colour; or 0% red, 75% green and 75% blue would produce a teal colour.

This colour system uses three channels, one for red, green and blue. As an example, in a digital image that has a colour depth of 24 bits, 8 bits (one byte) is reserved for each colour channel. (8x3 = 24).
See also: CMYK, PIXEL, Colour Depth

SD (Secure Digital) Cards

This card technology, introduced in late 2001, is a secure card technology adapted from the more popular MultiMedia Card standard and is backwards compatible with current MMC cards. The Secure Digital format includes several important technological advancements over MMC. These include the addition of cryptographic security protection for copyrighted data/music and a 4X increase in data transfer rates.

To help support higher-capacity cards, SD cards are slightly thicker than the original MMC cards. This means that digital cameras designed to support SD cards might also accept MMC cards, although this is not always the case. However, devices designed for MMC cards will not support the thicker SD cards. The SD Card Association sets the standards for Secure Digital cards.
See also: Compact Flash Card, MMC, Smartmedia Card, xD Picture Card, Sony Memory Stick

SmartMedia Cards

SmartMedia cards, introduced in 1996, are the thinnest flash storage devices. They were originally called SSFDC, for Solid-State Floppy Disk card, as they look like a miniature floppy disk. SmartMedia cards usually incorporate a single flash chip and do not incorporate a controller. Smartmedia cards are beggining to fade in favor of other flash memory card technologies.
See also: Compact Flash Card, MMC, SD Card, xD Picture Card

Sony Memory Stick

Sony Memory Stick is another flash memory technology that has come onto the market recently. Sony Memory Sticks (SMS) are about the size of a stick of gum. SMSs feature fewer connector pins, an Erasure Prevention Switch, a theoretical maximum capacity of 32 GigaBytes, high speed data transfers and support for data copyright protection and encryption.

TIFF

Tagged Information File Format. This format was originally developed by the now defunct Aldus Corporation as a flexible digital image format for desktop publishing. This format continues to be in common use today, with some digital cameras supporting it as an alternative format to JPEG. TIFF image files can support both lossy or lossless compression, or no compression at all. It is most common to see TIFF used with no compression.
See also: Lossless Compression, Lossy Compression, JPEG

TWAIN

A communication standard that allows computer software to retrieve digital images from any TWAIN compliant digital imaging devices (such as scanners or digital cameras). Most scanners come with what's known as a TWAIN driver, a standardized piece of software used to aquire an image from the scanner. Curiously enough, TWAIN is an acronym that stands for Technology Without An Interesting Name.

USB (Universal Serial Bus)

A widespread standard that allows computer peripherals (scanners, digital cameras, mouses, keyboards, printers) to connect and communicate with computer systems. USB devices are hot pluggable, meaning that they can be plugged in while the device and computer are powered.

This standard transmits data serially, or one bit at a time over a cable and operates at two different speeds. Many devices support the USB 1.1 standard which transmits data at 12 Megabites per second. The newest standard is USB 2.0 and it transmits data at a maximum rate of 480 Megabits per second.
See also: Bit, Megabit, Firewire.

USB Flash Drive

A flash memory device which plugs into a USB port. Flash drives are usually very small compact devices which can typically store anywhere from 16 megabytes up to 1 gigabyte of data. Very easy to use, you just plug the drive into a USB slot, and a drive letter or icon is automatically assigned by the computer's operating system. This allows the user to quickly and easily transfer files to and from a computer onto a flash drive.
See also: USB, xD Picture Card, MMC, SD Card, Smartmedia Card, Compact Flash Card.

xD Picture Card

Jointly developed by Fuji Photo Film Co., Ltd. and Olympus Optical Co., Ltd., for digital cameras, the relatively new xD Picture Card is the smallest storage format of its kind on the market. Comparable in size to a penny, measuring just 0.79” x 0.98” x 0.07” and weighing less than one-tenth of an ounce, this card has the potential to store up to 8GB of data on a single card.
See also: Compact Flash Card, MMC, SD Card, Smartmedia Card, xD Picture Card