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Please send me any new terms as they are
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AC (alternating
current) Form in which electricity is
delivered via direct wiring; an electrical
current that regularly reverses direction.
Invented by Nikola Tesla in 1884 and
promoted by Westinghouse, in competition
with Thomas Edison's DC current, which
flows constantly in one direction. The
rate of alternation of AC current is known
as frequency, measured in hertz (cycles
per second). House current is always AC;
battery power is always DC. (See DC,
hertz.)
alphanumeric Character
set or designation containing letters,
numbers and other characters, such as
punctuation marks.
analog Type of signal
that represents sound or video as a
continuously variable progression of
levels, often portrayed as waves. As
opposed to digital, which employs a
sequence of 2 types of pulses at otherwise
unvarying levels to represent binary
values (combinations of the numerals 0 and
1) to encode the signal. (See digital.)
aperture The lens
opening, which permits light to expose the
film in a traditional camera or the CCD
(charge-coupled device) in a digital
camera or camcorder. The aperture may be
either fixed or adjustable and is
calibrated in f-stop numbers (the higher
the number, the smaller the opening). In
higher-end cameras the aperture can be
manually set.
artifact(ing) Misinterpreted
information from a compressed image that
produces color imperfections or line
imperfections, which negatively impact the
image.
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audio record A digital
camera's ability to record audio sound to
accompany a still photo or MPEG (Moving
Picture Experts Group) movie.
automatic exposure setting Automatically
adjusts the exposure to match particular
light settings.
batteries
Digital camera batteries include: Nickle
cadmium (NiCad) rechargeable
batteries. They use an alkaline
electrolyte, have a longer life than
non-rechargeable and have memory. A nickel
metal hydride (NiMH) rechargeable
battery lasts longer than a NiCad and has
no memory. Lithium ion batteries
are more costly than the NiCad or NiMH,
but hold a charge much longer.
BIT (binary digit) The
most fundamental unit of digital
information. The higher number of bits,
the more shades of color that can be
reproduced.
bitmap Storing
information that maps an image pixel, bit
by bit. There are many bitmapped file
formats: BMP, PCX, PICT, PICT-2, TIFF, GIF
(89a), and so on. Most image files are
bitmapped. This type of file gives you the
"jaggies." When examined closely
you can see the line of pixels that
creates edges. Bitmap images are used by
all computers. The desktop or screen
information for all Windows machines uses
BMP files, while the Macintosh™ uses
PICT files.
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brightness The balance
of light and dark shades in an image.
Brightness is distinct from contrast,
which measures the range between the
darkest and lightest shades in an image.
Brightness determines the intensity of
shades; contrast determines the number of
shades.
burst mode Also referred
to as continuous shooting or rapid-fire
shots, this feature allows you to capture
multiple images in quick succession with
one touch of the exposure button. This is
a useful feature when shooting subjects in
motion. The number of shots a digital
camera can take in burst mode varies from
camera to camera.
contrast The
relationship between the light and dark
areas of an image. Contrast is the range
between the darkest and lightest shades in
an image, while brightness is the balance
of light and dark shades. Contrast
determines the number of shades;
brightness determines the intensity of the
shades. An image with low contrast tends
to look dull and flat.
continuous shooting Camera
feature that allows a camera to take
several rapid-fire exposures when the
shutter button is held down. This feature
is useful for shots where there is quick
action and you want to take multiple
shots.
cartridge The
electromechanical assembly in a turntable
that's used to convert the mechanical
vibrations picked up by a stylus
(phonograph needle) from a record's
grooves into electrical energy for
amplification; sometimes called a pickup.
(See moving-coil, moving-magnet.) Also, a
protective plastic casing or sleeve
containing magnetic or optical digital
data (recording or playback) media.
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charging time or recycling time This
time is measured between the flash and the
point of time when the ready indicator is
lit again. According to the DIN standard,
the ready indicator can be lit as soon as
70% of the full charge is reached.
CMOS (complementary
metal-oxide semiconductor) A new digital
camera technology. CMOS image sensors are
less expensive to manufacture than CCDs
(charged-coupled devices). CMOSs also
require less power to operate, bringing
down the cost of digital cameras that use
CMOS technology. CMOS chips also can
convert the analog image to digital and
manage some basic camera controls, among
other tasks.
CompactFlash Flash
memory card measuring 1.5 inches square,
developed by SanDisk; used in small
portable devices such as digital cameras,
MP3 players and PDAs, and available in a
variety of multi-megabyte capacities. (See
flash memory, Memory Stick, SmartMedia.)
continuous burst or capture mode The
ability to take multiple pictures in a
small amount of time. Great for action
shots.
CCD
(Charge-coupled device) A solid-state
image pick-up device that converts light
into an electrical charge; used as the
image sensor in digital cameras and
camcorders (analogous to film in a
traditional camera) and in other digital
imaging devices such as scanners. It is
the chip within a digital camera or
digital camcorder that converts the
brightness and color information from the
lens into digital data.
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data compression Digital
cameras don't have the massive amounts of
storage a computer does, yet they create
files that can be quite large. Because of
this, the camera compresses the data to
make the optimum use of the limited space
available. The less compression used, the
better the image. The more compression
used, the more images can be stored.
depth-of-field The zone
where all elements in a picture are in
focus.
digital System that uses
binary numbers, 0 and 1, representing
"on" and "off," to
record, reproduce and/or store text,
sound, images, video or any other kind of
data.
download Process of
transferring data between computers,
Generally refers to moving information
from a larger or more remote storage
device to a smaller or more local one
(e.g., from an Internet server to your PC
or from your PC to a portable MP3 player).
DPI (dots per inch)
Indicates resolution of a peripheral as a
measurement of the number of horizontal or
vertical dots it's able to resolve in
input or output. (See PPI and resolution)
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dynamic range The
ability of the camera's CCD to capture the
full range of shadows and highlights.
digital zoom
Digital method to radically increase a
camcorder's or camera's zoom ratio to
focus in on a distant subject, as opposed
to optical zoom, which uses lens movement
and has limited range. Digital zoom
enlarges the pixels in a digitized image,
reducing its effective resolution. Digital
zoom is a convenience, but optical zoom is
the critical measure of a camcorder's or
camera's magnification capacity. Some DVD
players also have digital zoom.
e-mail mode Sony
Mavica's e-mail mode reduces file sizes
for quick uploads and downloads.
f-stop Indicates the
relative size of the lens opening
(aperture) and is written, for example as
f/16. The larger the aperture, the smaller
the f-stop. Each number represents an
aperture that admits half as much light as
the preceding one.
file format The way the
image is saved. Several file formats are
available for use and each one has its own
advantages and disadvantages. The most
popular file formats include JPEG, GIF,
BMP, TIFF, PICT, EPS, and PCX.
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filter A colored or
specially coated piece of glass or other
transparent material used over the lens to
emphasize or modify the color or density
of the entire scene or certain areas
within a scene.
FireWire Apple
Computer's proprietary name for IEEE 1394
connectivity. (See IEEE 1394, i.LINK.)
flash Gives you
different lighting choices for your
pictures.
flash memory Type of
permanent RAM storage that is unaffected
by power loss (and so is referred to as
non-volatile); usually used in
battery-powered or portable electronic or
digital data storage devices, such as
digital cameras, portable MP3 players and
handheld PCs. May be permanently installed
or in the form of removable media, such as
SmartMedia, CompactFlash or Memory Stick.
(See CompactFlash, SmartMedia, Memory
Stick.)
flash range The maximum
distance from which a flash can
effectively illuminate a subject. Most
built-in flashes are effective to about
12-15 feet. Range varies by brand, so
check the specifications carefully.
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flash sync The ability
of a digital camera to add external flash.
focal length Lens view
measurement. A wide view lens (wide-angle)
has short focal length and a long view
lens (telephoto) has longer focal length.
focus range The range
within which a camera or camcorder is able
to focus on the selected picture subject;
e.g., 4'-infinity.
fps (frames per second)
Rate at which video or film images are
recorded and displayed. The NTSC video
standard is 30fps. (See NTSC.)
GIF (graphic interface)
Designed by CompuServe for using images
online. This is a 256-color or 8-bit
image.
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GIF 89 The most recent
GIF standard that allows the selection of
area for transparency. Primary use is on
the Internet and other online services.
Like GIF, it is 256-color or 8-bit
imaging.
GUI (graphical user
interface) Pronounced Gooey, refers to the
computer interface with a user-friendly
appearance.
gain Gain, or
“gain-up”, is the amount of ambient
light that enters the iris of a camcorder.
It electronically boosts the video signal
level to make subjects appear brighter in
low-light situations. (See gain-up
control.) It is also the reflectivity of a
projection screen. A gain of 1.0 equals
the reflectivity of a matte white surface.
A gain of 3.0 is high for a
front-projection screen, whereas 7.0 is
typical for rear-projection screens.
gray scale Black, white
and shades of gray, as applied to computer
graphics or imaging devices, such as a fax
machine or photocopier; the variations in
brightness that enhance clarity. In video,
the manner in which the color temperature
of a video monitor changes with the signal
level (black being at a low signal level,
white being at a high signal level, and
gray being in between); tracking color
accuracy. (See colorimetry, color
temperature.)
IEEE 1394 High-speed
digital video and data interface
technology adopted by the Institute of
Electrical and Electronics Engineers; a
nascent standard for connecting digital
television and computers to various
components and peripherals, such as
Digital VHS, set-top HDTV tuner boxes and
digital video camcorders. Apple Computer's
implementation is called FireWire; Sony's
is called i.LINK. (See FireWire, i.LINK.)
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i.LINK Sony's
proprietary name for IEEE 1394
connectivity. (See IEEE 1394, FireWire.)
image capacity The
number of pictures a digital camera can
store in its internal memory. Of course,
the more storage available, the more
pictures you can take before having to
"reload" (either by clearing the
on-board memory or inserting a new memory
card). The resolution of the pictures you
take also directly affects image capacity.
The higher the resolution of the picture,
the more memory it requires and the fewer
such images will fit into a given amount
of memory.
ImageMate An external
drive created by SanDisk to make
downloading data from a CompactFlash card
to a PC even easier. The drive connects to
a PC's parallel port and allows the
printer to piggy back on it.
image sensor The type of
device used in digital cameras and
camcorders to capture an image. The 2 most
common types are known as CCD
(charge-coupled device) and CMOS
(complementary metal oxide semiconductor).
Interface The method a
digital camera uses to connect to a PC or
notebook and download files. Common
methods include CompactFlash external
drives, SmartMedia floppy disk adapters,
floppy disk drives, serial cables, USB
cables, and infrared light.
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ISO equivalent
Conventional camera film is rated using
the International Standards Organization
(ISO), which determines the film speed.
The higher the ISO number, the
"faster" the film, meaning the
less light needed to take a picture.
Although digital cameras do not use
traditional film, the industry uses an ISO
equivalency rating to describe their light
sensitivity.
JPEG (Joint Photographic
Experts Group) An internationally
recognized organization responsible for
compression standards for digitized still
images; the encoded format defined by this
organization is among the most common
formats for compressed digital still
images used on the Web (the other being
GIF). It incorporates a variable
compression scheme that allows users to
select varying degrees of image integrity
vs. file size.
kilobyte 1024 bytes,
written KB. Used to refer to the size of
files, relates to the amount of
information in a file.
LCD (liquid crystal
display) Type of display used by digital
cameras so users can view images before
they take a picture as opposed to the
small viewfinder of a camera. They also
can use the LCD to review the pictures
taken. Many digital cameras use them to
make camera operations easier with menu
driven commands, multiple image viewing,
and improved help functions.
MB (megabyte) 1024
kilobytes. Used to refer to the size of
files or media, such as floppy disks and
removable memory cards. Refers to the
amount of information in a file or how
much information can be contained on
storage devices like a 1.44MB floppy or
16MB SmartMedia.
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megapixel Refers to one
million pixels on the CCD. Cameras with a
resolution of 1024 x 768 don't yet qualify
for the megapixel category as they only
have 786,432 pixels. Cameras with a
resolution of 1280 x 1024 and above do
belong in the megapixel category. Double-megapixel
refers to cameras with 2 million pixels on
the CCD. These cameras yield near
photo-quality prints and are the camera of
choice for people who are concerned about
printed output, including families,
business people and semiprofessional
users.
Memory Stick A flash
memory format that can be erase-protected;
shaped like a stick of gum -- hence the
name. Developed by Sony for use in digital
cameras, camcorders and other small
devices; a competitor of SmartMedia and
CompactFlash flash media. (See
CompactFlash, SmartMedia, flash memory)
movie mode In this mode,
long sequences of low-resolution (160 x
120 pixels) images are captured in very
rapid succession (at 0.1 or 0.2 second
intervals). The resulting movies can be
played back directly on the camera's
screen, or downloaded as composite images
to a host computer, where they can be
assembled back into a movie via software.
MPEG movie mode Sony
Mavica's ability to record full motion
video and sound onto one floppy disk in
MPEG file format.
MPEG
(Motion Picture Experts Group) Pronounced
EM-peg, an organization that establishes
standards in computerized digital video
compression and reproduction. MPEG schemes
reduce the data stream by storing only the
changes from one frame to another, instead
of each entire frame. MPEG compression
also removes some image data, but the
reduction of data is generally
imperceptible to the human eye.
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noise Unwanted
electrical signals that produce spots on
the image.
offline Digital cameras
with internal memory.
online These cameras
have no internal memory and must be
connected to a computer to be used.
output Any electronic or
digital signal, transmission, visual
image, printout or digital data emanating
from a device such as a computer, TV,
tuner or CD player. Also, a jack that
emits a signal. Always connected to an
input.
parallax error With a
lens-shutter camera, parallax error is the
difference between what the viewfinder
sees and what the camera records,
especially at close distances. This is
caused by the separation between the
viewfinder and the picture-taking lens.
There is no parallax error with
single-lens-reflex cameras because when
you look through the viewfinder, you view
the subject through the picture-taking
lens.
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parallax focus Focusing
system in some compact cameras that
compensates for the difference between
viewfinder and lens placement.
PCMCIA card (Personal
Computer Memory Card International
Association) card. Used in digital cameras
to transfer photos to a notebook or PC.
PCX Windows Paintbrush
bitmap image standard.
PICT The native
bitmapped file format for Macintosh
images.
PICT 2 The native color
bitmapped image format for Macintosh, up
to 32-bit color.
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picture effects Built-in
programming modes such as Sepia and
Negative Art create unique color and
contrast settings for the pictures you are
going to take.
pixelization The
square-like pattern of a video image that
becomes more apparent as the image is
enlarged, revealing the individual pixels
that make up the image.
PPI
(pixels per inch) The amount of pixels per
inch at which an image is displayed or
printed affects its output quality. For
example, if the image is to be displayed
on a monitor, 72ppi to 100ppi is
sufficient. If the image is to be printed,
it should have at least between 150ppi to
300ppi to reduce the effects of
pixelization. (See DPI and resolution)
pixel (picture element)
A pixel is a single point in a digitized
or digital image. Pixels are made up of
elements to produce a specific color. In a
digital image file, a pixel is made up of
numeric values representing shades of
three colors red, green, and blue (RGB).
In a 24-bit image file each RGB color has
a total of 256 shades possible, combining
the 256 shades for each of the 3 colors
with the possibility of up to 16,777,216
possible colors for each pixel.
RGB (red green blue)
Computers and other digital devices handle
color information in shades of red, green,
and blue.
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resolution
The density of pixels in an image that a
device such as a digital camera can
achieve. Higher pixels per inch (PPI)
produces a finer level of detail.
- Optical:
This resolution is most important. It
is the maximum resolution that the
camera’s chip can capture.
- Interpolated:
Software enhanced resolution.
Interpolated resolution artificially
creates more pixels in the image.
scripting
Scripting, from Kodak, is like software
for the camera. The camera can:
- Take the
same picture with different exposures
to ensure the best shot.
- Add the
date, text, and time to your images.
- Calculate
picture quality and compression to
allow 1 more picture.
- Provide
the assistance of a photo expert who
walks the user through a series of
questions to help get the right photo.
sensitivity Response of
an electrical circuit or transducer to a
given input. Speaker sensitivity is tested
by driving the speaker with a broadband
signal at a strength of 2.83 volts, or 1
watt, and measuring the acoustical output
of the speaker at a distance of one meter.
Often referred to interchangeably as
efficiency.
shift register The area
of the CCD that catalogs the image and
converts it from analog to digital before
it is sent to memory.
shutter speed The
camera's shutter opens and closes when you
take a shot, allowing light to hit the
film or image sensor. Shutter speed refers
to the amount of time the shutter stays
open and is measured in fractions of a
second. A very fast shutter speed can
capture clear images of fast action, like
horse races, while slow shutter speeds are
better suited to shots of static subjects
like sunsets or city lights.
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signal-to-noise ratio (See
S/N.)
SLR viewfinder An SLR
viewfinder allows the photographer to see
up to 95 percent of the captured image,
clear and centered. Serious photographers
love an SLR's ability to frame precisely
and create sharp, focused pictures.
SmartMedia Flash memory
card, smaller than either PC cards or
CompactFlash cards. Originally developed
by SanDisk but now available from a
variety of manufacturers. SmartMedia cards
are used in small portable devices, such
as digital cameras, MP3 players and PDAs.
They are available in a variety of
multi-megabyte capacities. (See flash
memory, Memory Stick, CompactFlash)
SmartMedia floppy disk adapter An
adapter to make downloading files from a
SmartMedia card to a PC even easier.
Simply insert the SmartMedia card into the
adapter and insert the adapter into the
floppy disk drive to view, edit and print
images.
S/N (signal-to-noise
ratio) Comparison of maximum signal
strength against the nominal background
noise generated by a device or medium to
indicate how clean the signal is -- for
instance, how much background noise will
be heard when a tape is played. Not
actually a ratio; expressed as the
difference between the 2 values in
decibels. The larger the difference, the
better the performance of the device or
medium.
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storage size Digital
cameras store their images as electronic
files, like the files on the hard drive of
a computer. The more storage space, the
more images the camera can store. Like
computer storage, digital camera storage
is measured in megabytes (MB). Most
cameras have between 2 and 8MB of internal
storage, but many offer removable storage
devices that can store as much as 250MB or
more.
storage
There are 4 types of storage media for
digital cameras: the 3.5-inch floppy disk,
the SmartMedia card, the CompactFlash card
and Sony's Memory Stick. SmartMedia,
CompactFlash and Memory Stick media can
store several megabytes of data which can
be downloaded by connecting the digital
camera to a PC with a serial or USB cable,
or by using a special adapter (card
reader). Disks are used in Sony Mavica
digital cameras.
time-lapse photography The
ability to take pictures in increments of
time to later play them back like a movie.
For example, you could watch the petals of
a flower unfold in the morning.
transducer Device that
converts one type of energy -- electrical,
acoustical, magnetic or mechanical -- into
another. Examples include a phono
cartridge, magnetic record or playback
head, speaker, microphone or cathode ray
tube (CRT).
upload Process of
transferring data between computers.
Generally refers to moving information
from a smaller or more local storage
device to a larger or more remote one
(e.g., from a digital camera to your PC or
from your PC to an Internet bulletin
board).
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video out A port on a
digital camera that allows it to send
still images to a television.
viewfinder
Provides the photographer with an
approximation of what the lens is seeing.
- SLR
(single lens reflex): Allows you to
see through the same lens that the
photo will be taken through.
- Rangefinder:
Uses a separate viewfinder which
approximates what the lens is seeing:
works better in low-light conditions.
(See parallax error).
white balance The
camera's ability to correct color and
tint when shooting in different lighting
conditions.
whole disk copy Sony
Mavicas can copy disks right inside the
camera for immediate sharing of images.
Simply load images into memory, insert
an empty disk and copy the images to the
new disk. It can also copy files from
applications such as Word, Excel, and
Quicken.
zoom ratio In a camera
or camcorder, a proportional comparison
of the longest available focal length
with the shortest. A zoom lens ratio of
10:1, for example, means the image at
one end of the zoom range has 10 times
the magnification of the same image when
viewed from the other end of the range.
The larger the ratio, the more extreme
the available telephoto and wide-angle
effects.
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zoom lens
An adjustable lens that makes an object
appear closer or further away, for a
variety of framing options. There are
two types of zoom:
- optical
zoom: this zoom is produced by the
optical lens itself, similar to a
film camera. It produces
enlargements without degradation.
- digital
zoom: takes a small part of the
original captured frame and zooms it
digitally with interpolation. Causes
degradation above 2X to 3X zoom.
#
1/3 CCD image sensor (charge-coupled
device) A smaller and more durable
high-resolution sensor which provides
sharp picture detail and accurate color
reproduction. Because of the smaller
size and weight, this sensor fits into
smaller, compact digital cameras and
camcorders.
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