This Photography Glossary contains
an alphabetical listing of many of the terms used in photography,
accompanied by definitions. In a number of cases, more in-depth
information on the term can be found by clicking the text links
- Achromatic Lens: An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic
spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus in the same plane.
- Active-Matrix Display: A type of flat panel LCD display used in laptop and portable computers. Active matrix displays produce a superior image to passive matrix displays.
- Additive Colors: The three additive primary colors are red, green and blue. When these three colors of light are mixed in equal proportions they will produce white light. Also known as additive primaries.
- Advanced Photo System: Sometimes referred to as APS. The new imaging system centered around a new film cartridge, with cameras, film, and photo finishing all talking to one another to avoid errors, produce pictures of the best quality, and organize these pictures for easy retrieval.
- Advanced Photo System Cassette: The film cartridge loaded into the camera and then used to store the processed negatives. It has indicators to show if the film a) is new b) has been used (exposed) partly c) has been used (exposed) completely d) has been processed. If the Film has been completely used or processed, the cassette cannot be put back into the camera.
- Advantix: Eastman Kodak's brand name for their APS products.
- Airbrushing: A software tool found in many image editing programs that simulates the effect of a mechanical airbrush.
- Aliasing: The visual stair-stepping of edges that occurs in an image when the resolution is too low. This can be caused by improper image sampling or improper image processing.
- Angle of view
- Anti-Aliasing: A technique used to smooth the transition between adjacent image areas. The removal or softening of jagged (aliased) edges by averaging or blending techniques.
- Aperture: This is the opening in the lens that controls how much light goes through to the film. Apertures are marked in f/stops. The smaller the number, the larger the aperture.
- Archive:Storage of selected digital files for backup or long-term storage.
- Artifact:Unwanted visual anomalies or defects generated by an input or output device, or by a software operation, that degrade image quality.
- Artificial Intelligence: The use of computers to solve problems and process information in ways that approximate human thought.
- Aspect Ratio: The relationship of an image's horizontal length and vertical height. The horizontal length number is placed first (i.e. 3:2).
- Aspheric Lens:
- Available Light
Up to two lines of information, like
exposure data, time, date, location can
be printed on the back of each picture.
This information can be recorded in the
camera or later be put on with special
- Barrel Distortion:
distortion that spreads the center
dimensions of the picture.
- Base Resolution:
The Photo CD image resolution (512 x 768
pixels) that is formatted for display on
current consumer televisions.
- 4 Base:
The 1536 x 1024 pixel image that is
scanned and stored on a Photo CD. This
image is ready to be used by High
Definition Television Systems.
- 16 Base:
The 2048 x 3072 pixels image that is
scanned and stored on a Photo CD and
suitable for digital imaging and desktop
- 64 Base:
The maximum resolution image file that
is available on Pro Photo CD disks. This
4000 x 6000 pixel file produces a 72
megabyte color image.
- Baud Rate:
Used interchangeably with "Bits Per
Second." The unit of measure used to
rate the speed at which computer data
can be translated via modem. Typical
modem rates are 2,400, 9,600, 14,400,
and 28,000 baud.
Graphics that are constructed of
out of an array of dots. Each dot is
represented by either a single number or
a set of three or even four numbers
ranging from 0 to 255. Photo CD and
Photo Floppy images are bitmap images.
fourth color in four-color printing. It
is listed as the K in "CMYK." Black is
required in the printing process because
equal amounts of cyan, magenta and
yellow inks will not produce a true
Printing term referring to an image or
inked area which extends to the edge of
a printed piece. The bleed is the
portion of the artwork that is beyond
the trim marks of the piece. The bleed
is required to account for any slight
misalignment during trimming which would
otherwise result in an unprinted strip
of paper appearing at the edge of the
In computer graphics software, the
intermediate steps between two objects
that are created when the objects are
merged together via a specified number
of intermediate transformations.
- BPI (Bits
A term defining the density of data in a
- BPS (Bits
A measurement of the speed of data
transfer, used interchangeably with the
term baud per second. In many image
editing programs, this is the term
describing a special effects filter that
performs a specific function, such
smoothing selective edges. In some
cases, the image editing programs
present the brushes as an icon that
actually looks like a brush.
- Bubble Jet:
Canon ink jet printing technology that
creates bubbles in the ink supply and
propels the ink through small nozzles
onto the print media.
Part of the computer's memory used for
temporary storage of information. This
becomes necessary to compensate for
differences in speed that different
devices can transmit or receive data.
A data pathway used within a computer
system to transfer information within
A bundle of data containing eight bits.
This is the common size unit for
- C format: A 4x6 print.
The Classic print format, best for
close-ups of people.
Video camera and video recorder in one
unit. Very portable, compact and
A process of setting digital imaging
components to standardized settings that
will produce accurate and predictable
results in the output.
Acquiring information, such as an image,
with a scanner or digital camera device.
- CCD Array:
An arrangement of CCD sensors mounted in
close proximity that allows for the
simultaneous capturing of many pixels
with one exposure.
A compact disc format that allows
storage of information in a read only
A CD format that allows the users to
record data to a disc when using the
proper hardware. Recorded data is not
(CD-ROM Extended Architecture):
A specific type of compact disc-read
only device that is compatible with the
Photo CD format and other CD
applications. Multiple session Photo
CD's cannot be fully utilized on non-XA
The hue or color information associated
with an image.
The portions of a signal that are
dedicated to describing the hue and
saturation. Used in measuring the
difference between two colors of equal
- CMY (Cyan,
These three subtractive primary colors
are used in color-negative printing and
in some color output devices to produce
a full gamut of color. The combination
of pure CMY inks produces black, and the
elimination of all three produces white.
- CMYK (Cyan,
Magenta, Yellow and Black):
The four colors of ink that are used in
"four color process" printing to create
the appearance of a photographic or full
color. Black is added to compensate for
the lack of purity in CMY inks.
A system of software and/or hardware
that matches the colors between two or
more digital devices. Color calibration
systems commonly compare device color
profiles and translate one color model
into a device-independent language that
the next color device can use.
The process of adjusting an image to
compensate for scanner deficiencies or
output device characteristics.
A graphic mechanism for displaying color
measurements and for making color
changes to an image. User adjustments to
the angle and slope of the curve
implement color changes to one or all of
an images color channels.
- Color Key:
A printer's proofing system developed by
3M that makes separate acetate sheets of
CMYK that when stacked give a
representation of the offset printing of
a color image.
Management System (CMS):
A combination of software and or
hardware devices used to produce
accurate color results throughout a
digital imaging system.
Refers to the component colors used in
the image, such as RGB or CMYK. This is
also called a Color Space or Color
The electronic or photographic process
of separating a single RGB color image
into the three subtractive primary
colors CMY plus K (black) that will be
used for reproduction. These four
monochrome films are used to produce the
plates in four color printing.
A scale used
to refer to the visible energy system of
various light sources. The scale uses
degrees Kelvin as a measure of the
mixture on a scale from red to blue
white. Daylight = 5500 Kelvin, a
blue-white color. The Tungsten in a
light bulb produces about 3200 Kelvin,
an orange color.
A device for measuring color values.
A video signal that includes the
luminance and chrominance signals, along
with the burst signal and sync signals.
Composite video signals are transmitted
over a single wire. The standard
The process of reducing the size of a
data file, usually accomplished through
software processing. This is used to
reduce the required storage space or cut
Term used to describe a specific piece
of software for a computer system.
Sometimes referred to as an application.
A method of applying an image onto an
offset printing plate. The image is
transferred from a computer directly to
the device that exposes the image onto
the plate, bypassing the need for
separations and film.
Terminology sometimes used to describe a
computer monitor and keyboard. Contact
Print: A photographic print made from a
negative or positive original in contact
with a photographically sensitive film,
paper, or printing plate.
The measure of difference between the
lightest and darkest values appearing in
an image. High-contrast images contain
mainly dark values and white values with
few steps or tones available in the
One of the three subtractive primary
colors. Produced by mixing equal amounts
of blue and green projected light. Cyan
is also one of the four colors used in
A picture that is in computer language.
Because the picture is represented by a
series of numbers, it is very easy and
improve the image or to alter it.
computer's rendition of an image. These
digital images can be retouched and
enhanced and then printed.
(Dynamic Random Access Memory):
The term describes memory within the
computer that is constantly changing.
(Digital Audio Tape):
A recording format that is commonly used
for data storage and data backup because
of its low cost per megabyte.
The numbers that make up a digital file.
The process of reducing the size of a
data file, usually accomplished through
A device used to measure the density of
light transmitted or reflected by paper
or film. It is used to check the
accuracy, quality and consistency of an
The degree of opacity of a photographic
A feature of some scanners that allow
them to eliminate moiré patterns that
A single unit from which all data is
Information or data that exists as
numerical values (1 or 0) based on a
binary coding system.
A filmless camera system. Any camera
system that is capable of converting an
analog image info a digital signal or
Any printing device that is capable of
translating digital data into hardcopy
The process of sampling analog data and
converting (quantizing) the signal into
a digital data format usable by a
to use memory without a software
Printing devices that allow for the
elimination of film separations from the
printing process. These systems utilize
a computer controlled system employing
lasers to "write" digital data to a
plate that is already mounted on the
spelling variation of "disk" referring
to compact discs such as Photo CD or
A process used by some output devices to
simulate shades of gray or color
variations with a randomizing technique
that uses varying sizes and shapes of
pixel groupings instead of an ordered
array of halftone dotes.
Dots make up an image in color
separations or halftones. Halftone dots
will have a fixed density but have
variable size (amplitude modulation).
- Dot Gain:
The effect produced by the expansion of
individual dots in a halftone screen
when printed onto paper. Dot gain
results in a darkening of a printed
image and is influenced by the tendency
of different papers to absorb ink.
- Dot Matrix:
An impact printing process that uses a
series of dots to create all images,
lines and text.
- Dot Pitch:
The distance between the dots on a
computer monitor, typically 0.2 to 0.3
millimeters. The closer the dots the
sharper the image on the monitor.
- DPI (Dots
The unit of measure used to describe the
resolution of image files, scanners, or
output devices. The measure of distinct
pixels that a device can produce either
horizontally or vertically in one inch.
- DSLR (Digital Single Lens Reflex) A digital still image camera that uses a single lens reflex (SLR) mechanism. Most professional cameras have always been single lens reflex cameras, although analog. Digital SLRs began to emerge in the early 1990s, but became very popular after the turn of the century. Following are the two major differences between DSLRs and standard digital cameras.
Sublimation (Diffusion Transfer):
A color printing technology that forms
the image by delivering gaseous dyes to
the receiver material with a thermal
driver. This creates near photographic
The side of photographic film or paper
coated with the silver emulsion. Film
output is specified as emulsion up, or
Encapsulated PostScript (EPS):
A file format developed by Adobe that
stores graphics and text as Postscript
language commands that a printer can
read and print. These files contain low
resolution preview files in addition to
the high resolution Postscript commands.
Fuji's brand name for their APS
A screening technology used in digital
continuous tone printers where
fixed-sized dots are placed based on
image detail and tone values to enhance
sharpness and detail while avoiding
Film Status Indicators, the icons on the
end of the cassette indicating whether
the film is unexposed, partially
exposed, fully exposed but not
technique in many image editing programs
that allows for the softening of the
edge around a selection.
The particular arrangement of digital
information that is saved from an
application program. The method of
arrangement or storage is unique for any
particular application program, but most
applications can import and export
standardized graphic and text file
formats, such as TIFF, GIF, and EPS
graphics; or RTF or ASCII text.
The relative index, also called ISO, of
how much light a film requires to be
properly exposed. A 100 ISO film
requires four times the light of a 400
ISO (speed) film for correct exposure.
Rule of thumb: Dull day-high speed,
bright day-low speed
Software that is used to modify digital
images by altering the values or
arrangement of selected image pixels.
An image file format developed and
supported by Eastman Kodak Co.,
Microsoft Corp., Hewlett-Packard, Live
Picture and other companies. The format
uses FITS see FITS) technology to
facilitate the transmission and
manipulation of large image files.
A scanner which utilizes CCD linear
arrays, where the image is placed on a
glass platen, and the CCD array moves
past the artwork.
A type of recording head on a VCR or
camcorder whereby there is no static
when stopping and starting between
measurement (in millimeters) that
determines how big an image will be.
It's the focal length which determines
the perspective, i.e., wide angle
A 4x7 print.
Similar to the motion picture and HDTV
The process of reproducing a continuous
tone image as a series of various sized
dots within a fixed grid that can be
reproduced with ink on a printing press.
The finer the dot grid the higher the
quality of the reproduction.
A television system that incorporates
1000 or more horizontal lines of
resolution (twice current standards)
along with a wider aspect ratio and
digital quality audio.
A scale used for measuring the number of
cycles per second.
An alternative printing process that
extends the capabilities of printing
presses. This system uses stochastic
screening, 6-color printing, and other
techniques to expand the possible color
gamut well beyond that of traditional
The brightest/lightest area within an
The number of vertical lines that a
system is capable of producing (counted
on a horizontal axis).
Saturation, and Brightness):
A color model that utilizes Hue,
Saturation, and Brightness as the three
Saturation, and Value):
A color model that utilizes Hue,
Saturation, and Value as the three
One of the components of color. The hue
can be specified by the particular
wavelengths or by CIE coordinates.
The effect of changing an object's level
- GIF (Graphics Interchange Format):
A graphics file format common to online
services and the Internet. A GIF
utilizes a Ito 8-bit palette to minimize
file size (pronounced "jiff").
- Gigabyte (GB):
Approximately one billion bytes (1000
Megabytes). The exact number is
- Gray Scale (or Grayscale):
An image containing a range of gray
levels as opposed to only pure black and
One of the three additive primary colors
of light (Red, Green and Blue)
(Intensity, Hue, and Saturation):
color model where colors are expressed
by three values representing Intensity,
Hue, and Saturation. Ink Jet: A
nonimpact printing technology where ink
droplets are propelled at the paper to
form characters or graphics.
Irreversible Processed Indicator, a tab
on the cassette. Depressed or broken in
photofinishing to serve as an
alternative indicator that the cassette
has been processed.
This is the
designation for how the camera, film and
photofinishing equipment communicate
with each other. There are two types of
Information Exchange. Optical
Information Exchange simply exposes
marks on the film in a reserved area.
This is used to tell the photofinisher
what format of picture you selected (C,
H, or P)
when the photo was taken. Magnetic
Information Exchange has even more
information. It can tell the
photofinisher about the conditions that
the picture was taken so that it can be
printed to its best. It can also record
greetings and information (date, time,
name of event, etc.) which can be
printed on the back (see
A 4x7 print
with small images of the pictures on
your roll of film. the index print makes
for easy identification to match
pictures to negatives.
(.JPG)(Joint Photographic Experts Group):
A graphics file format designed for use
with photographs and other color
bitmaps. The JPEG format uses
compression algorithms and an
"averaging" technique to create files
that are smaller than would be the case
with other graphics file formats. Saving
an image as a JPEG files does cause a
very minor loss of image data and in
some cases, quality.
1,024 bytes of computer memory.
A temperature measuring scale used to
describe the color of light. The lower
the color temperature the redder the
light, and the higher the color
temperature the bluer the light.
The fine adjustment of the spacing
between pairs of type characters in a
word to create visually pleasing and
Landscape, Landscape Mode:
The orientation of an image that is
wider than it is tall; a setting
controlling an output device to properly
fit a computer document to the print
capability of APS cassette which enables
the active light lock door to be opened
and the film strip to be thrust into the
camera body for loading.
A concept often referred to as
brightness that refers to the amount of
perceived light reflecting or emanating
from a subject; also refereed to as
- Line Art:
Artwork that is only black and white,
with no other tones included.
A term referring to the organization of
elements of a halftone printing screen.
Normally used to define the density of
the screen; i.e. a 133 Line Screen
refers to a pattern with 133 halftone
dots/inch. A higher or "finer" line
screen will create a sharper, more
- LPI (Lines
See "Line Screen"
The lightness or brightness of an image.
A concept and control in some software
that changes or imports only the color
lightness information within an image.
A term used to identify a photograph
which is taken at a very close distance
to the subject. Normally so close the
image size on the negative is 1-to-1 or
A predetermined pattern of key strokes
that are activated to save time when
doing a repetitive task on the computer.
A subtractive primary color for
printing. It is made up of equal parts
of red and blue projected light.
1,048,576 million bytes of computer
A unit of measure for frequency that
relates to the processing speed of a
computer. Equal to one million hertz.
A visual defect that occurs in half-tone
printing when the dots of the different
separations used to create the half-tone
image are at the wrong angles (See
(Motion Pictures Expert Group):
A motion picture compression system.
Film containing a reversal of an image,
such that the values of the original are
reversed with light becoming dark, and
Concentric multicolored rings caused by
the pressing of film to glass. This can
be a problem in scanning from negatives
image editing applications, a random
pattern of unwanted pixels or pixel
groupings called artifacts.
category has a focal length of 50mm for
Nikon's brand name for their APS
(Optical Character Recognition):
Software that allows the computer to
convert documents that have been scanned
and saved in a graphics format back into
- Offset Printing (Offset Lithography):
A common printing process that makes
prints by transferring ink to a rotating
"blanket" that contacts the paper.
A 4x10 print. The panoramic format,
perfect for wide shots.
- PAL (Phase
A standard for video that is common in
Western Europe, Australia and other
The range of color or tone available in
the imaging process, or a movable menu
of tools or options found in software
camera format which crops the top and
bottom of the negative resulting in a
long skinny photograph, with an illusion
A company producing numerous color
matching systems for print and computer
applications. The PMS color matching
system is commonly used to represent
3000 distinct colors through a numbering
Matching System (PMS):
A printing industry-standard set of
term common in computer imaging
referring to a picture element.
A unit of measurement used in the
graphic arts industry. There are 12
points to a Pica. One point equals
approximately 1/72 inch. See "Postscript
With these cameras you are looking
through a separate window (viewfinder)
instead of through the lens. These
cameras are less expensive, smaller and
easier to carry. The disadvantages are
under-powered flash, increased red-eye
problems and limited flexibility to add
other lenses, flashes, etc.
The orientation of an image that is
taller than it is wide; a setting
controlling an output device to properly
fit a computer document to the print
- PPI (Pixels
Often used interchangeably with DPI, PPI
refers to the number of pixels per inch
in an image.
A color that is the basis for all other
color combinations. The primary colors
are Red, Green and Blue (RGB) in light;
Cyan, Magenta and Yellow (CMY) in color
photographic printing. In offset color
printing, black (K) is added to CMY inks
to more accurately reproduce an image.
The colors Cyan, Magenta, Yellow, plus
Black, used for offset printing.
(Random Access Memory):
The high-speed portion of the computer's
memory that is held on special chips for
use in current applications or
An image that is defined as a collection
of pixels arranged in a rectangular
array See "Bitmap."
Changing vector type image information
to raster image information.
An additive primary color.
Refers to print material that is viewed
with the light on the same side of the
image as the viewer.
Applying shading and lighting effects to
a two dimensional image to create the
look of a three dimensional object.
measure of how closely packed the dots
in a bitmapped image are, often
expressed in dots per inch (dpi) or
lines per inch (lpi). The higher the
number, the higher the quality. However,
doubling the resolution of an image
results in a computer file four times as
large, requiring more hard disk space
and computer memory to handle the higher
quality image. Resolution is also used
to describe how close together a
computer printer can print dots in an
image. Again, the larger the number, the
higher the quality. It is important to
know the capability of the printer's
resolution before scanning an image in
order to get enough information to print
the best quality.
The particular pixel density of an
image, or the number of dots per inch a
device is capable of recognizing or
producing. See "DPI" and "PPI."
Removing imperfections or unwanted
portions of an image.
A color model using red, green, and
blue; the additive primary colors. Video
display systems use RGB data to create
- RIP (Raster
A processor used to convert information
from a graphics application into raster
data for output on a printer.
A memory type that cannot be changed or
rewritten, and will not lose information
when a computer is shut down.
The amount of chroma present in a color.
Pastels are low saturation while bright
colors are said to be highly saturated.
The process of translating a picture
from artwork or transparency into
digital information. Screen Angles. In
half-tone printing, these are the angles
at which halftone screens are placed to
avoid moire patterns on the final image.
The most commonly used angles are: Black
= 45 degrees; Magenta = 75 degrees;
Yellow = 90 degrees; Cyan = 105 degrees.
The process of using screens or digital
methods to create halftone screen
representations of continuous tone
- SCSI Port:
The connection used by SCSI devices to
connect to the CPU. Often SCSI devices
are used in a series called a "Scuzzie
brightness or luminance of an image when
compared to a gray scale.
Detail or information contained in dark
areas of an image.
The darkest tone printable in an image
without being black. All tonal values
below this threshold will print as
The process of copying ROM information
A picture enhancement making the image
have more distinct borders, areas, lines
A masking or image blocking that
isolates and image from the background.
A mounted 35mm transparency designed for
look into the viewfinder in these
cameras you are actually looking through
the camera lens. They are highly
flexible. You can change lenses as you
choose as well as most other accessories
for creative picture-taking.
Fuji's brand name for their APS
A process that softens, blurs or makes
an image, color or pattern to appear out
Device used to measure the quality and
accuracy of a color monitor and the film
or paper output.
- Spot Color:
A single color ink used independently in
a printed piece, as opposed to a process
color which is used in overlapping
combinations of other process inks to
create any of a large spectrum of
These are the three colors that are used
to create all other colors in color
photographic printing. (Cyan, Magenta
To place one element over another to
create stacking of images or overlays.
This category has a focal length that is
greater than 50mm for 35mm cameras and
makes the subject seem closer.
A technology that uses heat to deposit
dye on a receiver material.
- 32 Bit
A digital image format that incorporates
256 shades in 8-bits for each of three
color channels (RGB) and includes a mask
(alpha) channel with a possible 256
levels of opacity.
A small low resolution version of an
(Tagged Image File Format):
A common bitmap image format developed
by Aldus. TIFFs can be black-and-white,
grayscale or color.
Some percentage of a solid ink. Tints
are created by using a screen to create
the impression of a lighter color when
the ink is printed onto paper or another
Metal in filament of bulbs creating
illumination when electronically
charged. Tungsten= 3200 Kelvin an orange
A digital color model that uses eight
bits each for the three additive colors
red, green and blue; creating more than
16 million colors.
The sharpening of an image by creating
contrast at contrasting edges of the
To decompress a file (usually text)
using PKUNZIP or WinZip, two popular
programs. The decompression takes place
automatically when a Zip compressed file
is opened (See Zip).
Minolta's brand name for their APS
A computer image that uses mathematical
descriptions of paths and fills to
define the graphic, as opposed to
A transition from one color or intensity
The result of combining the additive
primary colors (Red, Green and Blue).
The lightest tone printable in an image.
All tone values above this threshold
will print as white.
a focal length that is less than 50mm
for 35mm cameras and gives a wider field
A subtractive primary color for color
printing and printing. It is made up of
equal parts of red and green projected
To compress a file (usually text) using
PKZIP or WinZIP, two popular programs.
Commonly used to reduce the size of a
file to speed up transmission over the
internet or an on-line service.
Making the image or image part become
larger (zooming in) or smaller (zooming
out) as it appears on the monitor.