A/D
Converter |
A device
that converts analog information (a photograph or video frame) into
a series of numbers that a computer can store and manipulate. All
digicams use an A/D converter, the higher the bit rate the better
the output. Modern hi-res digicams employ a 12-bit or 14-bit A/D
to increase the dynamic range (range of light from highlight to
shadow). |
AA
cell |
In the digicam world
this refers to the most common power source, the AA-size battery.
See also "NiCd" and "NiMH" and check here: NiMH
Batteries/Chargers |
AA
Filter |
Most digital SLR cameras
employ a Low Pass Filter (LPF) or Anti-Aliasing (AA) filter in front
of the imager to help eliminate color aliasing (moire) problems.
|
AC
Power |
Running your digicam
off the wall outlet power rather than by battery power. Usually
means purchasing optional AC power adapter. |
Add-On
Lens |
Some lenses have filter
threads on the front edge that allow you to mount an auxiliary wide
angle or telephoto lens in addition to the standard lens. |
AE |
Auto Exposure, a system
for automatically setting the proper exposure according to the existing
light conditions. There are three types of AE systems:
Programmed where the camera picks the best
shutter speed and aperture automatically
Aperture Priority, the user chooses an
aperture value and the shutter speed is automatically determined
by lighting conditions
Shutter Priority, the user chooses a shutter
speed and the aperture is automatically determined by lighting conditions
|
AE
Lock |
The ability to hold
the current exposure settings and allow you to point the camera
elsewhere before capturing the image. This is usually accomplished
by half-pressing the shutter button and keeping it at that position
until you're ready to capture the image. |
AF |
Auto Focus. A system
that automatically focuses the camera lens. |
Aliasing |
An effect caused by
sampling an image (or signal) at too low a rate. It makes rapid
change (high texture) areas of an image appear as a slow change
in the sample image. Once aliasing occurs, there is no way to accurately
reproduce the original image from the sampled image. |
Algorithm |
A mathematical routine
that solves a problem or equation. In imaging, the term is usually
used to describe the set of routines that make up a compression
or color management program. |
Angle
of View |
The angle of view is
calculated by the focal length of the lens and the size of the image
sensor. Consumer digicam focal lengths are usually stated in terms
of their 35mm film equivalents. For digital SLR cameras with interchangeable
lenses it's more difficult as different cameras have different size
sensors. Use this online lens calculator to view the angle of view
of a lens on any of today's popular dSLR cameras. |
Anti-aliasing |
The process of reducing
stair-stepping by smoothing edges where individual pixels are visible. |
Aperture |
The lens opening formed
by the iris diaphragm inside the lens. |
Aperture
Priority AE |
Exposure is calculated
based on the aperture value chosen by the photographer. This allows
for depth of field (DOF: Range of focus) control - large aperture
= shallow DOF and a small aperture = deep DOF. |
Archive |
A collection of data
in long-term storage |
Artifact(ing) |
Misinterpreted information
from a JPEG or compressed image. Color faults or line faults that
visibly impact the image negatively. |
Aspect
Ratio |
The ratio of horizontal
to vertical dimensions of an image. The most common aspect ratio
in digicams is 4:3 so that images "fit" properly on computer
screens (800x600, 1024x768, 1280x1024). Some cameras offer a 3:2
mode so that you can print "perfect" 4x6" prints
with no cropping necessary.
(35mm film is 3:2, TV sets are 4:3, HDTV screens are 16:9) |
Aspherical
Lens |
A lens whose edges
have been flattened so that it is not a perfect sphere, produces
a superior image. |
Automatic
Exposure |
The camera automatically
adjusts the aperture or shutter speed or both for the proper exposure. |
Autofocus |
The camera lens focuses
automatically, usually when the shutter release is half-pressed.
|
Back
Lit |
Movie clip in Windows'
AVI format. See "Movie clip" |
AWB |
Automatic White Balance.
A system for automatically setting the white balance in today's
digital cameras. See also "White Balance" |
B&W |
Term used to mean black
and white |
Back
Lit |
The subject is heavily
lit from behind which generally causes it to be underexposed unless
you use critical spot metering. |
Banding |
An artifact of color
gradation in computer imaging, when graduated colors break into
larger blocks of a single color, reducing the "smooth"
look of a proper gradation. |
Barrel
Distortion |
A common geometric
lens distortion causing an acquired image to pucker toward the center
and be "rounded" along the outer edges. See examples of
it at Andromeda's LensDoc page. |
Bit |
The smallest unit of
memory; a contraction from 'binary' and 'digit'. Binary digits are
0 and 1, also known as ons and offs. |
Bit
Depth |
This refers to the
color or gray scale of an individual pixel. A pixel with 8 bits
per color gives a 24 bit image. (8 Bits X 3 colors is 24 bits.)
24 bit color resolution is 16.7 million colors. |
Bitmap |
The method of storing
information that maps an image pixel, bit by bit. There are many
bitmapped file formats, .bmp, .pcx, .pict, tiff, .tif, .gif, and
so on. Most image files are bit mapped. This type of file gives
you the 'jaggies', when examined closely you can see the line of
pixels that create the edges. |
Bleed |
Printing term referring
to an image or linked area that extends to the edge of the printed
piece. |
Blooming |
A visual effect caused
by overexposing a CCD to too much light, This "digital overexposure"
can cause distortions of the subject and/or color. |
Blue
Tooth |
The new wireless standard
for connecting cameras, PDAs, laptops, computers and cell phones.
Uses very high frequency radio waves. Blue Tooth devices when in-range
(less than 30 feet) of each other easily establish a connection. |
BMP |
BitMapped graphic file
format popular with Windows computers. This is an uncompressed file
format like TIFF. |
Borderless |
Means a photo print
with no border around it. Old term for this was full-bleed printing. |
Bracketing |
see Exposure Bracketing |
Brightness |
The value of a pixel
in an electronic image, representing its lightness value from black
to white. Usually defined as brightness levels ranging in value
from 0 (black) to 255 (white). |
Buffer |
A temporary storage
area usually held in RAM. The purpose of a buffer is to act as a
temporary holding area for data that will allow the CPU to manipulate
data before transferring it to a device. Also see DRAM Buffer |
Bulb |
This is a long time
exposure setting - shutter stays open for as long as you keep the
shutter release button held down. Time exposure mode. Similar to
bulb mode, only the photographer presses the shutter release once
to open the shutter and once again to close it. Largely superseded
by bulb mode on most cameras, for some reason. Odd, as I think T
mode is more convenient to use than bulb, and no harder to implement
on automated cameras. However, some cameras have a similar function
with their electronic shutter releases, even though it isn’t
called T mode. For example, Canon cameras which support the RC-1
infrared remote work like this in bulb mode. One press of the RC-1
shutter release opens the shutter; another press closes it. |
Burst
Mode |
The ability to rapidly
capture images as long as the shutter button is held down.Also called
Continuous frame capture. |
Byte |
An ensemble of eight
bits of memory in a computer. |
Calibration |
The act of adjusting
the color of one device relative to another, such as a monitor to
a printer, or a scanner to a film recorder. Or, it may be the process
of adjusting the color of one device to some established standard. |
Card
Reader |
A device that you insert
flash memory cards into to transfer the data to the computer. Much
faster than the serial port! See also "PCMCIA" and "PC
Card" and check here: Flash Memory Cards/Readers |
CCD |
Charged Coupled Device,
a light sensitive chip used for image gathering. In their normal
condition these are grey scale devices. To create color a color
pattern is laid down on the sensor pixels, using a RGBG color mask
(Red, Green, Blue, and Green) The extra Green is used to create
contrast in the image. The CCD Pixels gather the color from the
light and pass it to the shift register for storage. CCDs are analog
sensors, the digitizing happens when the electrons are passed through
the A to D converter. The A to D converter converts the analog signal
to a digital file or signal. See also "CMOS" below |
CD |
CompactDisc - read
only storage media capable of holding 650MB of digital data. |
CDR |
CompactDisc Recordable
- a CD that you can write to once that can not be erased but can
be read many times, holds 650~700MB of digital data. |
CDRW |
CompactDisc ReWriteable
- the newest kind of CD-R that can be erased and re-used many times,
holds about 450MB of data. |
Center-Weighted |
A term used to describe
an auto exposure system that uses the center portion of the image
to adjust the overall exposure value. See also "Spot Metering"
and "Matrix metering" |
CF |
see CompactFlash and
check here: Flash Memory Cards/Readers |
Channel |
One piece of information
stored with an image. True color images, for instance, have three
channels-red, green and blue. |
Chroma |
The color of an image
element (pixel). Chroma is made up of saturation + hue values, but
separate from the luminance value. |
Chromatic
Aberration |
Also known as the "purple
fringe effect." It is common in two Megapixel and higher resolution
digital cameras (especially those with long telephoto zoom lenses)
when a dark area is surrounded by a highlight. Along the edge between
dark and light you will see a line or two of purple or violet colored
pixels that shouldn't be there. |
CIFF |
Camera Image File Format,
an agreed method of digicam image storage used by many camera makers.
|
CMOS |
Complementary Metal
Oxide Semiconductor - Another imaging system used by digicams. It
is not as popular as CCD but the future promises us even better
digicams based on CMOS sensors due to the lower amount of power
consumption versus the typical CCD device. |
CMS |
Color Management System.
A software program (or a software and hardware combination) designed
to ensure color matching and calibration between video or computer
monitors and any form of hard copy output. |
CMYK |
Cyan, Magenta, Yellow,
blacK; These are the printer colors used to create color prints.
Most color printers, Ink-Jet, Laser, Dye-Sublimation and Thermal
printers use these as their printer colors. (This is one of the
color management problems for computers. Converting RGB files to
CMYK files cause's color shifts.) When used by a printer the CMYK
is also known as a reflective color since it is printed on paper,
or reflective films. |
Codec |
Compresses information
so that it can be sent across a network faster, and decompresses
information received via the network. |
Color
Balance |
The accuracy with which
the colors captured in the image match the original scene. |
Color
Cast |
An unwanted tint of
one color in an image caused by a disproportionate amount of cyan,
magenta, and yellow. This can occur due to an input or output device. |
Color
Copier |
Color printing device
using electrostatic and CMYK Pigments. |
Color
Correction |
The process of correcting
or enhancing the color of an image. |
Color
Depth |
Digital images can
approximate color realism, but how they do so is referred to as
color depth, pixel-depth, or bit depth. Modern computer displays
use 24-bit True Color. It's called this because it displays 16 million
colors, about the same number as the human eye can discern. |
Color
Space |
Digital cameras use
known color profiles to generate their images. The most common is
sRGB or AdobeRGB and this information along with the camera and
exposure data is stored in Exif header of the JPEG file. This color
space information ensures that graphic programs and printers have
a reference to the color profile the camera used at the time of
exposure. see ICC Profile for more information. |
CompactFlash |
The most common type
of digicam flash memory storage. It is removable, small and available
in sizes from 4MB up to 1GB.
CF Type I the original 3.3mm high card
CF Type II cards and devices that are 5mm high.
Type I devices are all solid state but Type II devices include the
IBM/Hitachi Microdrive, a miniature, rotating hard drive.
and check here: Flash Memory Cards/Readers |
COM
port |
Your computer has serial
communication ports which support the RS-232 standard of communication.
This is the most common interface used to transfer data from a digicam
to the computer. |
Compression |
A digital photograph
creates an image file that is huge, a low-resolution 640x480 image
has 307,200 pixels. If each pixel uses 24 bits (3 bytes) for true
color, a single image takes up about a megabyte of storage space.
To make image files smaller almost every digital camera uses some
form of compression. See the "JPG" entry below. |
Continuous
Autofocus |
(Continuous-AF) The
autofocus system is full-time and works even before the shutter
release is pressed. |
Continuous
Tone |
An image where brightness
appears consistent and uninterrupted. Each pixel in a continuous
tone image file uses at least one byte each for its red, green,
and blue values. This permits 256 density levels per color or more
than 16 million mixture colors. |
Contrast |
A measure of rate of
change of brightness in an image. |
CR-V3 |
This is a 3V lithium
battery used in many Olympus brand (and other) digicams. It lasts
much longer than alkaline but it is also more costly. |
CRW
/ CR2 |
The raw CCD file format
used by Canon digicams. Abbreviated from CanonRaW. Canon also has
newer CR2 raw format as well. |
Dark
Frame |
A noise reduction process
whereby a camera takes a second exposure of a black frame after
the camera takes a long exposure (1/2-second or longer) image. The
image "noise" is easily identified in the black frame
shot and is then electronically removed from the actual image. This
helps reduce the amount of hot pixels that normally show up in long
exposure shots from digital cameras. |
DC |
Direct Current. Battery
power as in 9v DC battery |
Decompression |
The process by which
the full data content of a compressed file is restored. |
Dedicated
Flash |
Describes an electronic
flash that is made to be used only with a specific model of camera.
Canon, Nikon, Olympus and other cameras have specific electrical
contacts in the hot shoe to pass TTL-metering and AF range data
to/from the flash unit. You can not use a dedicated Canon flash
on a Nikon camera for example. |
Densitometer |
A tool used to measure
the amount of light that is reflected or transmitted by an object. |
Depth
of Field |
depth of field (DOF)
The range of sharp focus. Controlled by the focal length and aperture
opening of the lens. A large aperture yields shallow DOF. Smaller
apertures yield deeper DOF. Here's an online - DOF Calculator (Be
sure to follow the directions when calculating the DOF for your
digital camera's lens -- it is NOT calculated using the 35mm equivalent
(i.e. 35-105mm) focal length often quoted in our reviews -- you
must use the real focal length of the smaller digital lens. The
site linked above has a listing of popular cameras and their real
lens specifications.) |
Diffusion
Dithering |
A method of dithering
that randomly distributes pixels instead of using a set pattern.
|
Digital
Film |
Term used to describe
solid state flash memory cards. |
Digital
Zoom |
A digital magnification
of the center 50% of an image. Digital zooms by nature generate
less than sharp images because the new "zoomed" image
has been interpolated. |
Digitization |
The process of converting
analog information into digital format for use by a computer. |
Diopter
Adjustment |
Adjusts the optical
viewfinder's magnification factor to suit the eyesight of the user.
Look for a knob or dial next to or beneath the viewfinder's eyepiece.
Not all cameras have this feature. |
Dithering |
A method for simulating
many colors or shades of gray with only a few. A limited number
of same-colored pixels located close together is seen as a new color.
|
DOF |
Abbreviation for Depth
of Field (see above). |
Download |
Transfer image data
from the camera to the computer using a cable attached to either
the serial port (slow) or USB port (faster.) |
DPI |
Dots per Inch. A measurement
value used to describe either the resolution of a display screen
or the output resolution of a printer. |
DPOF |
Digital Print Order
Format. Allows you to embed printing information on your memory
card. Select the pictures to be printed and how many prints to make.
Some photo printers with card slots will use this info at print
time. Mostly used by commercial photo finishers or those Kodak kiosks
you find in the mall. |
DRAM |
Dynamic Random Access
Memory. A type of memory that is volatile - it is lost when the
power is turned off. |
DRAM
Buffer |
All digicams have a
certain amount of fixed memory in them to facilitate image processing
before the finished picture is stored to the flash memory card.
Cameras that have a burst mode have much larger DRAM buffers, often
32MB or larger. This also makes them more expensive. |
DSLR |
Digital SLR (Single
Lens Reflex) camera. Interchangeable lens digital camera. Manufacturers
include Canon, Fuji, Kodak, Nikon, Olympus, Pentax and Sigma. See
our DSLR Camera Reviews listing. |
DVD |
"Digital Versatile
Disc"
DVD is DVD-Video recorded on a DVD-R or DVD-RW disc, which contains
superior quality video (MPEG-2) and audio. Typically, a DVD can
hold more than one hour of video.
DVD Video Parameter Settings
Frame Size: 720x480 (NTSC) or 720x576 (PAL)
Frame Rate: 29.97 frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: 4~8 Mbps CBR or VBR (Constant/Variable Bit Rate)
Audio Settings: Stereo, 48 kHz and 192~384 kbps MPEG audio |
Dye
Sub |
Dye Sublimation is
a printing process where the color dyes are thermally transferred
to the printing media. Dye sub printers use the CMYK (cyan, magenta,
yellow, black) color format and have either three ribbons (cyan,
magenta and yellow) or high-end printers have four CMY plus a blacK.
The paper is run in and out of the printer four times, once for
each color and then a fourth time when a protective overcoat is
applied. Dye sub is continuous tone printing, it prints tiny square
dots each of which is denser in the center and lighter on the edges.
These dots can be varied from almost no dot at all to an almost
completely solid dot. The dyes are transparent so different colored
dots can be printed on top of each other to form any one of 16-million
colors. This is known as the subtractive color process. Dye sub
prints rival conventional photographs in both their color gamut
and longevity with water and UV resistant qualities.
For the sake of accuracy we must state that most printers today
that claim to be dye sub type printers are actually dye diffusion.
The complete technical name for this process is Dye Diffusion Thermal
or "D2T" printing. To achieve true sublimation printing
requires a laser to vaporize the dye material. The common 4x6"
dye sub or the bigger ones that do up to 8x10" prints like
the Olympus P-400 or Kodak Pro 8500 heat the dye material with a
thermal printhead and use pressure rollers to push the ribbon into
contact with the paper and then diffusion occurs. |
Dynamic
Range |
A measurement of the
accuracy of an image in color or gray level. More bits of dynamic
range results in finer gradations being preserved. |
E-TTL
/ E-TTL II |
Canon's flash exposure
system used on their digital SLRs. To quote Canon: "The “smarter”
E-TTL II system captures the subject as a “plane” and
ensures that images containing various colors and levels of reflection
are captured accurately and optimally. The system compares the ambient
light with the reflected pre- flash off the subject reported in
all 35 metering zones and selects the areas with a small difference
to be weighted for flash exposure calculation. This system also
eliminates or under weights areas with large difference recognizing
them as an extremely reflective object in the background or as a
highly reflective subject, smartly ensuring it by considering the
distance information data provided from compatible EF lenses. The
system similarly prevents over-exposure when photographers lock
focus and recompose the shot by considering the flash output level
calculated according to the broader distance." |
EPP |
Enhanced Parallel Port
- the newer hi-speed, bidirectional printer port on modern computers.
Some older digicams and scanners use the EPP port to transfer data. |
ERI-JPEG |
Extended Range Imaging
Technology, a new file format used in Kodak professional digital
cameras. This proprietary technology offers an innovative image
file format similar to a JPEG, but with the dynamic range and color
gamut information of raw DCR camera files. Extended Range Imaging
Technology files allow you to easily open, edit, and print JPEG
files within your JPEG workflow. Your JPEG files are captured directly
in the camera. With ERI, you'll have the extensive editing, color
balance, and color compensation capabilities of RAW digital negatives
for applying to your JPEG files. |
E-TTL |
Canon's Evaluative-TTL
exposure system that uses a brief pre-flash before the main flash
to calculate the exposure index. |
EV |
Exposure Value, a very
complex thing but in the digicam world it usually means the ability
to override the auto exposure system to lighten or darken an image. |
EVF |
Electronic ViewFinder,
a small color LCD with a magnified lens that functions as an eye
level viewfinder. Usually found on video camcorders but they have
been showing up on super-zoom digicams where optical viewfinders
are impractical. (Canon Pro90, Fuji 2800Z, Olympus C-2100, Nikon
Coolpix 5700). |
EXIF |
EXIF (Exchangeable
Image File format) refers to the embedded camera and exposure information
that a digital camera puts in the header of the JPG files it creates.
Many graphic programs (Photoshop, ThumbsPlus, Qimage Pro, CameraAid)
can read and display this information. |
Exif
Print |
Exif Print (Exif 2.2)
is a new worldwide printer independent standard. Under Exif 2.2,
the digital still camera can record data tags for specific camera
settings and functions such as whether the flash was on or off,
if the camera was in landscape, portrait or night scene mode, etc.
Referencing some or all of this information, an Exif Print compatible
application can process digital camera images intelligently based
on specific camera settings and the shooting environment.
See the Exif Print-CIPA web page for more info. |
Exposure |
The amount of light
that reaches the image sensor and is controlled by a combination
of the lens aperture and shutter speed. |
Exposure
Bracketing |
the camera automatically
takes a series of 3 or 5 pictures and slightly varies the EV for
each frame. This insures that at least one of the pictures will
be as close to perfectly exposed as possible. |
Exposure
Compensation |
Lighten or darken the
image by overriding the exposure system. Also known as EV Compensation. |
f-stop |
A numerical designation
that indicates the size of the aperture. It is inversely proportional
as a smaller number like F2.8 is a large opening and a large number
like F16 is a relatively small opening. |
FDD |
Floppy disk drive,
the most common being a 1.44MB 3-1/2" drive like those used
in today's PC computers. |
Field
of View |
please see FOV below.
|
File |
A collection of information,
such as text, data, or images saved on a disk or hard drive. |
File
Format |
A type of program or
data file. Some common image file formats include TIFF, JPEG, and
BMP. |
Fill
Flash |
Using the flash to
lighten shadow areas or just to provide more overall illumination
in situations where you normally wouldn't use the flash. Outdoors
in bright light you get very stark shadows underneath of people's
noses, chins and etc. Toggle the flash setting to "forced on"
or "fill" and the flash will now fire on every shot. It
also gives your human subjects that special little sparkle in their
eyes. |
FireWire |
Also known as "iLink"
and officially designated as the IEEE 1394 protocol. A high-speed
data interface now being used on digital camcorders and some high-end
digital still cameras. |
Firmware |
An often-used micro
program or instruction set stored in ROM. Usually refers to the
ROM-based software that controls a unit. Firmware is found in all
computer based products from Cameras to Digital Peripherals. |
Fixed
Aperture |
Normally when a zoom
lens goes from wide angle to telephoto the aperture changes. If
the camera has an option to fix the aperture value then it remains
constant regardless of focal length. |
Fixed
Focal Length |
A term that describes
a non-zoom lens, it is fixed at a given focal length and is not
variable. |
Fixed
Focus |
A lens that is preset
to a given focus distance, it has no autofocus mechanism, set to
give the camera the maximum depth of field |
Flash |
A built-in flash supplies
auxiliary light to supplement natural or available lighting conditions
often resulting in better color, better exposure, and improved picture
sharpness. |
Flash
Memory |
This is the "film"
for digital cameras, it can be erased and reused many times. It
is non volatile memory, data is preserved even when it is not under
power. They are several major types used in digital cameras; CompactFlash,
SmartMedia and Memory Stick. |
Flash
Memory Reader |
See Card Readers
see: Flash Memory Cards/Readers. |
Flashpath |
A device that allows
a SmartMedia card to be inserted into a regular floppy diskette
drive and its data transferred to the computer. There is also now
a Flashpath device for Memory Stick cards too. |
Flat
Bed Scanner |
An optical scanner
in which the original image remains stationary while the sensors
(usually a CCD linear array) passes over or under it. The scanned
material is held flat and scanned using a reflective process. |
Floppy
Disk Adapter |
A device that resembles
a 3-1/2" floppy diskette and allows a SmartMedia cards or Sony
Memory Stick modules to be read in a standard 1.44MB floppy disk
drive and check here: Flash Memory Cards/Readers |
Focal
Length |
A lens' angle of view,
most commonly indicated as wide angle, normal or telephoto. Usually
compared to a 35mm camera's lenses as in "the camera has a
wide angle lens equivalent to a 38mm lens on a 35mm camera."
See also "Zoom Lens" |
Focus
Assist |
Some cameras employ
a visible or invisible (infrared) lamp to illuminate the subject
so the autofocus can work in low light or total darkness. |
Focus
Lock |
Pre-focusing the camera
and then moving it to re-compose the image before capturing it.
Accomplished by half-pressing the shutter button and keeping it
held at that position while moving the camera to another point before
pressing it all the way to capture the image. |
FOV |
Field of View - The
area covered by the lens' angle of view. This is important to those
with a digital SLR camera using lenses designed for 35mm film cameras.
The manufacturers specify the FOV for these lenses when used on
a 35mm camera but not when they're used on a modern dSLR camera.
See the link below to calculate lens FOV's for most Canon, Fuji,
Kodak, Nikon, Pentax and Sigma dSLR cameras.
Click here to open the lens calculator (pop-up window) |
FPX
- FlashPiX |
Trade name for a new
multi-resolution image file format jointly developed and introduced
in June 1996 by Kodak, HP, Microsoft and Live Picture. |
Frame |
One of the still pictures
that make up a video. |
Frame
rate |
The number of frames
that are shown or sent each second. Live action relates to a frame
rate of 30 frames per second. |
Full
Bleed |
Printing term used
when an image or inked area extends to the edge of all four sides
of the printed piece. Better known as "borderless" in
today's world of inkjet photo printers. |
Gamma |
A measure of the amount
of contrast found in an image according to the properties of a gradation
curve. High contrast has high gamma and low contrast low gamma. |
Gamma
Correction |
In reference to displaying
an image accurately on a computer screen, Gamma correction controls
the overall brightness of an image. Images which are not properly
corrected can look either bleached out, or too dark. For more info
on gamma, go here |
Gamut |
The range of colors
that are available in an image or output process. It is generally
used in describing the capabilities of a printer to reproduce colors
faithfully and vibrantly - i.e. "The xxxxx printer has a wide
color gamut." |
GIF |
A graphic file format
used mainly for Web graphic or small animated files. Not good for
photos as it only contains a maximum of 256 colors. |
Gigabyte
(GB) |
A measure of computer
memory or disk space consisting of about one thousand million bytes
(a thousand megabytes). The actual value is 1,073,741,824 bytes
(1024 megabytes). |
Gradation |
A smooth transition
between black and white, one color and another, color and no color. |
Gray
Level |
The brightness of a
pixel. The value associated with a pixel representing it's lightness
from black to white. Usually defined as a value from 0 to 255, with
0 being black and 255 being white. |
Gray
Scale |
A term used to describe
an image containing shades of gray rather than color. Most commonly
referred to as a black and white photo. |
Guide
Number |
The output power rating
of a electronic flash unit. |
HAD
CCD |
Sony's latest CCD imager,
HAD = Hole Accumulation Diode |
Halftone
Image |
An image reproduced
through a special screen made up of dots of various sizes to simulate
shades of gray in a photograph. Typically used for newspaper or
magazine reproduction of images but it is also how today's inkjet
printers work. Halftoning or dithering are the methods used to produce
a smooth gradation of color versus distinct bands of color or moirè
patterns. |
HD |
Hard drive (aka HDD),
the internal, large-capacity data storage unit in today's PC computers. |
HDTV |
High Definition Television.
New video "standard" that will resolve 1,125 lines in
the United States instead of the traditional 525 lines of the NTSC
standard. The aspect ratio is 16:9 versus 4:3 of regular TV sets. |
Histogram |
A bar graph analysis
tool that can be used to identify contrast and dynamic range of
an image. Histograms are found in the more advanced digicams and
software programs (graphic editors) used to manipulate digital images.
The histogram shows a scale of 0 - 255 (left to right) with 0 being
black and 255 being white. |
Hot
Shoe |
A flash connector generally
found on the top of the camera that lets you attach a flash unit
and trigger it in sync with the shutter. |
Hologram
Laser AF |
Sony introduced a new
laser-assisted auto focus system on the Cyber-shot DCS-F707 that
uses a safe Class 1 laser to paint a grid on the subject that makes
the auto focus fast and accurate. Also found on the DSC-F717, F828,
V1 and V3 cameras. |
Hue |
A term used to describe
the entire range of colors of the spectrum; hue is the component
that determines just what color you are using. In gradients, when
you use a color model in which hue is a component, you can create
rainbow effects. |
i-TTL |
Nikon's new flash exposure
system, used on new D70 digital SLR and SB-600 and SB-800 Speedlights. |
ICC
Profile |
The International Color
Consortium, a group that sets standard guidelines for color management
in the imaging world. Click here to read their FAQs about color
management and ICC profiles and the like. Most printers, monitors
and scanners as well as digital cameras, usually come with a driver
disc for Windows and Mac systems that includes ICC profiles for
the particular device. Color profiles simply let one piece of hardware
or software "know" how another device or image created
its colors and how they should be interpreted or reproduced. |
IEEE-1284 |
This is the high-speed
bidirectional parallel port specification used on Windows PCs mostly
for printers. |
IEEE-1394 |
Better known as "FireWire"
- it's a high-speed input/output bus used by digital video devices,
film/flatbed scanners, high-end digital still cameras & PCs.
|
iESP |
Olympus' exposure metering
system. |
iLink |
Sony's term for IEE-1394
FireWire data port found on their camcorders. |
Image
Processing |
Capturing and manipulating
images in order to enhance or extract information. |
Image
Resolution |
The number of pixels
per unit length of image. For example, pixels per inch, pixels per
millimeter, or pixels wide. |
Image
Sensor |
A traditional camera
exposes a piece of light-sensitive film, digital cameras use an
electronic image sensor to gather the image data. See "CCD"
and "CMOS" as well as "Interlaced" and "Progressive
Scan" |
Image
Stabilization |
An optical or digital
system for removing or reducing camera movement in telephoto zoom
lenses. Usually found only on extremely long focal length lenses
such as the 10X lens on Sony Mavicas and Olympus C-2100UZ, E-100RS.
Can also be found on Panasonic FZ1/FZ2/FZ10's 12X Leica zoom lenns. |
InfoLITHIUM |
Sony's "smart"
lithium rechargeable battery pack. It has a chip inside that tells
the camera how long (in minutes) it will last at the current discharge
rate. |
Inkjet |
A type of printer that
sprays dots of ink onto paper to create the image. Modern inkjet
printers now have resolutions of up to 2880dpi and create true photo-quality
prints. |
Interlaced |
Term used to describe
an image sensor that gathers its data by first processing the odd
lines and then the even lines. See also "Progressive Scan"
for the other (preferred) method. |
Interpolated |
Software programs can
enlarge image resolution beyond the actual resolution by adding
extra pixels using complex mathematic calculations. See "Resolution"
below |
Intervalometer |
Fancy term for Time-Lapse.
Capture an image or series of images at preset intervals automatically.
|
Interval
Recording |
Capturing a series
of images at preset intervals. Also called time-lapse. |
IR |
InfraRed (aka IrDA)
uses an invisible (to humans) beam of light to either wirelessly
control a device or as a method of transferring data from camera
to computer (or printer) without cables. Some cameras also employ
infrared in the auto focusing system. |
ISO |
The speed or specific
light-sensitivity of a camera is rated by ISO numbers such as 100,
400, etc. The higher the number, the more sensitive it is to light.
As with film, the higher speeds usually induce more electronic noise
so the image gets grainier. ISO is the abbreviation for International
Standards Organization. (In the good old days it was known as the
"ASA film speed.") |
Jaggies |
Slang term for the
stair-stepped appearance of a curved or angled line in digital imaging.
The smaller the pixels, and the greater their number the less apparent
the "jaggies". Also known as pixelization. |
JFIF |
A specific type of
the JPG file format. Also known as EXIF |
JPEG |
Joint Photographic
Experts Group - The name of the committee that designed the standard
image compression algorithm. JPEG is designed for compressing either
full-color or grey-scale digital images of "natural",
real-world scenes. It does not work so well on non-realistic images,
such as cartoons or line drawings. JPEG does not handle compression
of black-and-white (1 bit-per-pixel) images or moving pictures.
See "JPG" below. |
JPEG2000 |
The new JPEG compression
standard that will be used in digital cameras and software starting
in 2002 (maybe?). It will feature higher compression but with less
image quality loss. |
JPG |
The most common type
of compressed image file format used in digicams. It is a "lossy"
type of storage because even in its highest quality mode there is
compression used to minimize its size.
See the official JPEG home page for even more details |
KB |
Can be used to mean
either a keyboard for a computer or more commonly "KB"
means a kilobyte of data. |
Landscape
Mode |
Holding the camera
in its normal horizontal orientation to capture the image. See Portrait
Mode. |
LCD |
Liquid Crystal Display.
Two types: (1) a TFT high-resolution color display device like a
tiny TV set. (2) A monochrome (B&W) information display using
black alphanumeric characters on a gray/green background. |
LED |
Light Emitting Diode.
All those wonderful little red, green and yellow indicator lights
used on cameras, power supplies and most electronic devices. |
Li-ion |
Some digicams are packaged
with a lithium-ion rechargeable battery pack. Lithium batteries
are lighter but more costly than NiMH or NiCd type of rechargeable
cells. Lithium cells can be recharged regardless of their state
of discharge, they're lighter in weight and maintain a charge better
in colder temperatures. Li-ion also holds a charge longer when idle. |
Lossless |
Storing the image in
a non-compressed format, see TIFF |
Low
Pass Filter |
Most digital SLR cameras
employ a Low Pass Filter (LPF) or Anti-Aliasing (AA) filter in front
of the imager to help eliminate color aliasing (moire) problems.
|
Mac |
Refers to the Macintosh
type of computers |
Macro |
The ability of a lens
to focus very close (less than 8") for taking pictures of small
objects at a 1:1 ratio. |
mAh |
A rating used in the
consumption of power of an electronic device such as an LCD or the
storage capability of a device like an NiMH or Nicad rechargeable
battery (i.e. 1600mAh cell). It stands for milliAmperehour. |
Matrix
metering |
In most digicams there
is a matrix metering option which uses 256 areas of the frame to
calculate the best overall exposure value.
see also: "Spot metering" and "Center-weighted" |
MB |
MegaByte, memory term
meaning 1024 KiloBytes. Used to denote the size of a flash memory
card such as 4MB, 8MB etc. (MB [megabyte] is often confused with
Mb [megabit], there's 8 bits in a byte so 256Mb = 32MB.) |
MD |
MiniDisc - Digital
recording media like a small floppy disc. This is common for audio
data and has been used on several digicams sold in Japan and Europe
but not in the U.S. yet. |
Megapixel |
CD resolution of one
million pixels. Digicams are commonly rated by Megapixels. You multiply
the horizontal resolution by the vertical resolution to get the
total pixel count:
1280 x 960 pixels = 1 Megapixel
1600 x 1200 pixels = 2 Megapixels
2048 x 1536 pixels = 3 Megapixels
2272 x 1704 pixels = 4 Megapixels
2560 x 1920 pixels = 5 Megapixels ... and so on |
Memory
Stick |
A flash memory card
standard from Sony. They resemble a stick of gum and currently (09/02)
come in sizes from 4MB up to 128MB.
also see: Flash Memory Cards/Readers |
Memory
Stick Pro |
The year 2003 upgrade
to Sony's Memory Stick flash cards. The new MS Pro cards are available
in 256MB, 512MB and 1GB capacities and offer faster read/write times.
All of Sony's digicams made in 2003 or after can use MS Pro cards.
|
Metering |
Used to calculate the
exposure from the existing light conditions. See: "Matrix Metering,"
"Spot metering" and "Center-weighted" |
Microdrive |
IBM/Hitachi miniature
hard disk drive for digital cameras and PDA devices. Packaged in
a CompactFlash Type II housing and available in 170MB, 340MB, 512MB,
1GB, 2GB, 4GB capacities. See my Microdrive user review |
miniCD |
The small diameter
(3-inch) CD discs. miniCD-R and miniCD-R/W discs are used in the
Sony Mavica "CD" series (CD200, CD250, CD300, CD400 and
CD1000) digicams. Their maximum capacity is ~165MB |
mm |
millimeter, measurement
to denote the focal length of a lens (i.e. 50mm) |
MMC |
MultiMedia Card, a
flash memory card used in some digicams and MP3 players. It is identical
in size and shape to the Secure Digital (SD) flash cards. and check
here: Flash Memory Cards/Readers |
Moirè |
A visible pattern that
occurs when one or more halftone screens are misregistered in a
color image. Often produces a colored checkerboard or rainbow pattern. |
MOV |
Apple QuickTime MOVie
file format. See "Movie clip" |
Movie
clip |
A sequence of motion
captured in AVI, MOV or MPEG format. Some digital cameras can capture
short movie sequences, some can also record the sound. |
Motion
JPEG |
A video sequence composed
of a sequence of JPEG compressed images. Abbreviated to MPEG (see
MEG below). |
MP |
Abbreviation for MegaPixel,
i.e. 1.5MP or 1.5MPixel |
MPEG |
Motion JPEG movie file.
See "Movie clip"
The digital video compression standard agreed upon by the Motion
Picture Expert Group, from the motion picture-computer industry. |
MPEG-EX |
Motion JPEG movie file
created by Sony cameras. This was the first motion video recording
sequence mode that was limited in length only by the amount of available
storage space. |
MPEG-HQX |
Motion JPEG movie file
created by year 2002 Sony cameras that incorporates the MPEG-HQ
(high quality, full-screen) and the unlimited recording capability
of MPEG-EX in 320x240 resolution. |
MPEG-VX |
Motion JPEG movie file
created by year 2003 Sony digicams. It is VGA resolution (640x480)
at 16fps with audio and the length is limited only by available
storage space. VX Fine is 30fps, very high quality. |
Multi-Pattern
Metering |
Exposure is determined
by reading many different zones in the frame. This yields a more
optimum exposure than those cameras using only a central zone metering
system. |
Multi-Point
Focusing |
The autofocus systems
uses SEVERAL different portions of the image to determine the proper
focus. |
Multi
Zone Focusing |
Many digital cameras
now offer multi zone focusing. The camera will automatically determine
which zone (center, left, right, upper, lower) to use to perform
the auto focusing. You no longer have to make sure that your subject
is dead-center to be properly focused. |
NEF |
Raw image data file
format used by the Nikon digital SLR (D1x, D100, etc) and some Coolpix
digicams. NEF means Nikon Electronic Format. |
NiCd |
Nickel Cadmium (aka
Nicad), a type of rechargeable battery. Nicad was the original type
of rechargeable battery and has been pretty much replaced by the
NiMH type. |
NiMH |
Nickel-Metal Hydride,
a type of rechargeable battery. NiMH is the more modern type of
rechargeable battery and has been touted as having no memory effect
as is common with Nicad type batteries when they are charged before
they have been fully discharged. NiMH may also be called NiHy by
some folks. and check here: NiMH Batteries/Chargers |
Noise |
Pixels in your digital
image that were misinterpreted. Usually occurs when you shoot a
long exposure (beyond 1/2-second) or when you use the higher ISO
values from 400 or above. It appears as random groups of red, green
or blue pixels. |
Noise
Reduction |
Some cameras that offer
long shutter speeds (exceeding 1 second) usually have a noise reduction
(NR) feature that is either automatic or can be enabled in the menu.
This is to help eliminate random "hot" pixels and other
image noise. |
NTSC |
Term used to describe
the 60 field video output (television) standard used in the U.S.
and Japan. See also "PAL" and "Video Out" |
OEM |
Original Equipment
Manufacturer. Means that the piece of equipment is made by one company
but labeled for and sold by another company. |
OLED |
Organic Light Emitting
Diode - Newly developed display technology that could replace LCD.
OLED does not require a backlight like LCD displays and therefore
is more energy efficient which is important to battery-operated
portable devices. It also offers increased contrast and a better
viewing angle which means it can be more easily viewed in bright
(sunlight) conditions. |
Optical
Viewfinder |
An eye level viewfinder
that is used to compose the photograph. |
Optical
Zoom |
Means that the camera
has a real multi-focal length lens, this is not the same as a "Digital
Zoom" which magnifies the center portion of the picture. |
ORF |
Olympus RAW format.
The unprocessed image format created by Olympus E1, E10, E20, E300
SLRs and C-5050, C-5060, C-8080 Zoom cameras. |
Orientation
Sensor |
A special sensor in
some cameras that "knows" when your turn the camera in
portrait orientation to take a vertical shot and "tells"
the camera to display it that way later when viewed on the TV screen
during playback. |
Overexposure |
An image that appears
too light. All the highlights and colors are totally lost and usually
unrecoverable even by software. |
PAL |
The 50 field video
format used primarily in Europe and other places outside of the
U.S. and Japan. See also "NTSC" and "Video Out"
|
Palette |
A thumbnail of all
available colors to a computer or devices. The palette allows the
user to chose which colors are available for the computer to display.
The more colors the larger the data and the more processing time
required to display your images. If the system uses 24-bit color,
then over 16.7 million colors are included in the palette. |
Panorama |
Capturing a series
of images to create a picture wider than what you could capture
in a single image. Requires special "stitching" software
to combine and blend the images into one finished image. |
Parallax |
An effect seen in closeup
photography where the viewfinder does not see the same as the lens
due to the offset of the viewfinder and the lens. This is a non-issue
if using the LCD as a viewfinder or if your camera is a SLR type. |
PC |
In camera terms it
denotes a type of flash synch connector, popular on most film cameras. In computer terms it
means a Personal Computer as in IBM-PC |
PC
Card |
Refers to a credit
card-sized device which can be a flash memory card, a network card,
a modem or even a hard drive. Comes in two flavors: Type I/II which
is a single slot height and Type III which requires a double-height
card slot. |
PCMCIA |
The card slots found
on laptop computers to use PC Cards. There are PCMCIA adapters for
CompactFlash, SmartMedia, Secure Digital, MultiMediaCard and Memory
Stick flash cards. |
Photo
CD |
Kodak's professional
service where they process your film and then scan the images using
a very expensive drum scanner and output these images to a CD. You
get several different sized resolution images of each of your film
pictures, from small to very large. PhotoCD is multi-session which
means more than one roll of pictures may be put on each PhotoCD
disc. |
PICT |
A graphics file format
used primarily on Macintosh computers. PICT files can contain both
object-oriented and bit-mapped graphics. There are two types: PICT
I and PICT II. PICT II is the current standard and supports color
up to 24-bit. |
PictBridge |
PictBridge is a new
standard for direct USB printing from digital cameras to inkjet
and dye sub photo printers without the use of a computer. To get
more information please go to the CIPA PictBridge web page. |
PictureCD |
Kodak's amateur service
of putting your camera images (1,534-by-1,024) onto a CD disc. 35mm
or APS camera pictures can be put on the PictureCD discs for about
$8.95 - $10.95 on top of regular processing fees. One roll per PictureCD.
|
PIM |
PRINT Image Matching
- Epson's new standard of embedded color and printing information
for digital cameras. Many of the camera manufacturers have joined
with Epson and now embed the PIM information in the Exif header
of the JPEG images created. Epson just announced at PMA 2002 the
new Exif 2.2 standard incorporating their PIM info. See the Epson
PIM web site. |
Pin-Cushioning |
A common geometric
lens distortion causing an acquired image to pucker toward the center,
usually found at telephoto focal lengths. See examples of it at
Andromeda's LensDoc page. |
Pixel |
The individual imaging
element of a CCD or the individual output point of a display device.
This is what is meant by the figures 640x480, 800x600, 1024x768,
1280x960 and etc when dealing with the resolution of a particular
digicam. Higher numbers are always better!! |
Pixelization |
The stair-stepped appearance
of a curved or angled line in digital imaging. The smaller the pixels,
and the greater their number, the less apparent the "pixelization"
of the image. Also known as the "jaggies". |
Plug-n-Play |
An automated installation
process used in MS Windows to connect peripherals to a computer.
When new devices are plugged into the computer the computer recognizes
the device and prompts the user to choose setup options and finish
installation. |
Polarizer |
A photographic filter
for eliminating glare and reflections. Just like your polarized
sunglasses get rid of annoying glare, the polarizer filter does
the same for your digicam. However - there are 2 types, linear and
circular. Linear is for film only, it screws up most auto focus
systems on digicams. Therefore be sure you use a circular polarizer
filter. It can also be used to darken skies. |
PNG |
An image file format.
PNG stands for Portable Network Graphics. It is a compressed file
format similar to JPG. |
Point
and Shoot |
A term used for a simple,
easy to use camera with a minimum of user controls. Generally the
user turns the camera on, aims it at the subject and presses the
shutter button. The camera does everything automatically. |
Polarizing
Filter |
A filter than helps
eliminate light reflections by limiting the angle of light that
reaches the lens. There are two types: Linear and Circular. Linear
type filters should not be used with digicams as they hinder the
auto focus system. The circular type filters can be rotated to adjust
to the light angle needed. |
PPI |
Pixels Per Inch -
A measurement to describe the size of a printed image. The higher
the number the more detailed the print will be. |
Pre-Flash |
Some digicams use a
low-power flash before the main flash to set the exposure and white
balance. This does not allow the use of a normal photo slave strobe
as it will be triggered by the pre-flash. |
Programmed
AE |
the camera picks the
best shutter speed and aperture automatically, also called "Automatic"
or "Point-n-Shoot" mode. |
Progressive
Scan |
Term used to describe
an image sensor that gathers its data and processes each scan line
one after another in sequence. See also "Interlaced" for
the other method. |
Prosumer |
Refers to more expensive
semi-professional digicams costing $1,000 and up. The average digicam
is made for the consumer market and costs well under $1,000. |
QuickTime |
A motion video standard
created by Apple. They have an entire QuickTime web site to explain
it. QuickTime video sequences can contain an audio track and are
stored as .MOV files. |
QVGA |
Refers to a Quarter-VGA
resolution (320 x 240) motion video sequences. |
RAM |
Random Access Memory
. The most common type of computer memory; where the CPU stores
software, programs, and data currently being used. RAM is usually
volatile memory, meaning that when the computer is turned off, crashes,
or loses power, the contents of the memory are lost. A large amount
of RAM usually offers faster manipulation or faster background processing.
|
Rangefinder |
The viewfinder on most
cameras is a separate viewing device that is independent of the
lens. Often mounted above and to the right or left of the lens.
It exhibits a problem known as parallax when trying to frame subjects
closer than five feet from the camera so it is advisable to use
the color LCD when shooting closeups for this very reason. |
RAW |
RAW files store the
unprocessed image data - at 12 bits per channel - from the camera's
imaging chip to its memory storage device. Lossless compression
is applied to reduce filesize slightly without compromising any
quality. RAW image files must be processed with special software
before they can be viewed or printed. The advantage is that you
have the ability to alter the white balance, exposure value, color
values, contrast, brightness and sharpness as you see fit before
you convert this data into the standard JPEG or TIFF format. Professional
digi-photographers import RAW image data directly into photo-editing
programs like Photoshop CS (which comes with a Camera Raw import
module that works with most popular RAW formats.) |
Red-Eye |
An effect caused by
an electronic flash reflecting off of the human eye and making it
look red. Compact cameras with the flash located close to the lens
suffer the worst from this problem. Pro photographers use a bracket
to hold an external flash unit above and off to the side of the
lens to eliminate red-eye. |
Red-Eye
Reduction Mode |
A special flash mode
whereby a pre-flash or a series of low-powered flashes are emitted
before the main flash goes off to expose the picture. This causes
the pupil in the human eye to close and helps eliminate red-eye.
|
Render |
The final step of an
image transformation or three-dimensional scene through which a
new image is refreshed on the screen. |
Resize |
Usually means to take
a large image and downsize it to a smaller one. Most graphic viewing
and editing programs offer a Resize option for this purpose. |
Resolution |
The quality of any
digital image, whether printed or displayed on a screen, depends
in part on its resolution—the number of pixels used to create
the image. More and smaller pixels adds detail and sharpens edges.
Optical Resolution is an absolute number
that the camera's image sensor can physically record.
Interpolated Resolution adds pixels to
the image using complex software algorithms to determine what color
they should be. It is important to note that interpolation doesn't
add any new information to the image - it just makes it bigger!
Camera makers often specify the resolution as: QVGA (320 x 240),
VGA (640 x 480), SVGA (800 x 600), XGA (1024 x 768) or UXGA (1600
x 1200) |
RF |
Range Finder - a type
of camera viewfinder that uses one lens to frame your subject and
another lens to capture the image. See "SLR" for the other
type. |
RGB |
Means Red, Green and
Blue - the primary colors from which all other colors are derived.
The additive reproduction process mixes various amounts of red,
green and blue to produce other colors. Combining one of these additive
colors primary colors with another produces the additive secondary
colors cyan, magenta and yellow. Combining all three produces white. |
RS-232 |
Standard type of serial
data interconnection available on most PC type computers. It's the
slowest way to transfer image data from a camera. Most digicams
made after 2001 do not use serial ports, they use the faster USB. |
Saturation |
The degree to which
a color is undiluted by white light. If a color is 100 percent saturated,
it contains no white light. If a color has no saturation, it is
a shade of gray. |
Scanner |
An optical device that
converts images - such as photographs - into digital form so they
can be stored and manipulated on computers. Different methods of
illumination transmit light through red, green and blue filters
and digitize the image into a stream of pixels. |
Scene
Modes |
Many digicams now have
an exposure mode called SCENE where the user selects the best pre-programmed
scene to suit the current shooting conditions. The camera will automatically
change many settings to capture the best possible image. |
SCSI |
A high-speed input/output
bus used mainly in Macintosh computers but also popular in many
high-end PCs. Abbreviation for Small Computer Systems Interface. |
SD |
Secure Digital card,
a flash memory card used in digicams and MP3 players. It is identical
in size and shape to the MultiMedia Card (MMC) flash cards. The
difference being that SD cards were designed to hold protected (copyrighted)
data like songs. Not all cameras that use SD cards can use MMC cards
so be sure to read your owner manual before buying additional cards.
and check here: Flash Memory Cards/Readers
Secure Digital - Secure Digital. See "SD"
above. |
Self
Timer |
Preset time delay (2,
5 or 10 seconds) before the shutter fires. Allows the photographer
to get into the picture without using a cable release or remote
control. It is also great for taking macro shots as you don't touch
the camera to trip the shutter and thus eliminates any camera shake. |
Sepia |
The (brown) mono-toned
images from the "good ole days" now often found as a special
image effect on some digicams. |
Serial
Port |
Same as "RS-232"
above. |
Shutter |
The physical device
that opens and closes to let light from the scene strike the image
sensor. Digicams use both electronic and mechanical shutters. |
Shutter
Lag |
The time between pressing
the shutter and actually capturing the image. This is due to the
camera having to calculate the exposure, set the white balance and
focus the lens. |
Shutter
Priority AE |
The user chooses a
shutter speed and the aperture is automatically determined by lighting
conditions. Shutter speed priority is used to control motion capture.
A fast shutter speed stops fast action, a slow shutter speed blurs
a fast moving subject. |
Skylight
Filter |
This is an UltraViolet
absorbing filter that helps overcome the abundance of blue in outdoor
photographs. Not really necessary in digital photography as the
camera's white balance system adjusts for the color temperature
of the scene. We do use them to protect the camera's lens from scratching,
fingerprints or dirt. |
Slow
Sync |
A flash mode in some
digicams that opens the shutter for a longer than normal period
and fires the flash just before it closes. Used for illuminating
a foreground subject yet allowing a darker background to also be
rendered. Good for night time shots of buildings with people in
the foreground. Often called Night Scene or Night Portrait mode. |
SLR |
Single Lens Reflex
- Means the camera has a viewfinder that sees through the lens (TTL)
by way of a 45°-angled mirror that flips up when the shutter
fires and allows the light to strike the image sensor (or film). |
SmartMedia |
(aka SSFDC), a flash
memory card that consists of a thin piece of plastic with laminated
memory on the surface and uses a gold contact strip to connect to
the camera. SmartMedia cards are available from 4MB up to 128MB
in size.
For more info see Flash Memory Cards/Readers |
Smoothing |
Averaging pixels with
their neighbors. It reduces contrast and simulates an out-of-focus
image. |
Spot
Metering |
The camera's auto exposure
system is focused on a very small area in the center of the viewfinder
to critically adjust the overall exposure value ONLY for that area.
see also: "Center-weighted" and "Matrix metering" |
SRF |
Sony raw format filetype
identifier. i.e. DSC00101.SRF |
SSFDC |
Solid State Floppy
Disc Card - See "SmartMedia" above |
Subtractive
Color |
Photographs and objects
of nature create color by subtracting or absorbing certain wavelengths
of color while reflecting other wavelengths back to the viewer.
This is called subtractive color. Example - The common apple, it
is seen as "red" by the human eye or a digital camera.
The apple really has no color (light energy of its own), it merely
reflects certain wavelengths of white light that cause us to see
red and absorbs most other wavelengths. Color paintings, color photography
and all color printing processes use the subtractive process to
reproduce color. In these cases, the reflective substrate is canvas
(paintings) or paper (photographs, prints), which is usually white. |
SuperCCD |
Fujifilm's image sensor
used in their line of digital cameras. For more information, read
their SuperCCD press release. |
SVCD |
"Super Video Compact
Disc"
A CD-ROM disc that contains high quality video and audio. Typically,
a SVCD can hold about 35~45 minutes (650MB) of video and stereo-quality
audio (depends on the data rate used for encoding). The video and
audio are stored in MPEG-2 format, much like a DVD. SVCD video has
better quality than VHS video.
SVCD Video Parameter Settings
Frame Size: 480x480 (NTSC) or 480x576 (PAL)
Frame Rate: 29.97frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: Variable bit rate up to 2600 kbps
Audio Settings: 32~384 kbps MPEG-1 Layer 2 audio bit rate |
SVGA |
SuperVGA refers to
an image resolution size of 800 x 600 pixels. |
Telephoto |
The focal length that
gives you the narrowest angle of coverage, good for bringing distant
objects closer. |
TFT |
Refers to the type
of hi-res color LCD screen used in digicams. TFT = Thin Film Transistor. |
Thermal
Dye Sublimation |
please see Dye Sub |
Thumbnail |
A small, low-resolution
version of a larger image file that is used for quick identification
or speedy editing choices. |
TIFF |
Tagged Image File Format
- An uncompressed image file format that is lossless and produces
no artifacts as is common with other image formats such as JPG.
|
Time-Lapse |
Capturing a series
of images at preset intervals. Also called Interval Recording or
Intervalometer |
USB |
Universal Serial Bus
- the data I/O port on most digicams and found on modern PC and
Mac computers. Faster than the serial port. Up to 12Mb/s with v1.1
interfaces.
USB 2.0 - The newest USB standard, close
in throughput speed to FireWire now. Up to 400Mb/s.
It's important to note that many manufacturers
are now "duping" the buying public by using statements
like - "Equipped with a full-speed USB 2.0 interface"
which unfortunately means that it's really just a USB 1.1 interface
that will transfer data at up to 12Mb/s with newer USB 2.0 computer
interfaces. What you should look for is a statement that says "Equipped
with a high-speed USB 2.0 interface." The specification for
a high-speed USB 2.0 interface is data transfer up to 400Mb/s. |
UV
Filter |
This is an UltraViolet
absorbing filter that helps overcome the abundance of blue in outdoor
photographs. Not really necessary in digital photography as the
camera's white balance system adjusts for the color temperature
of the scene. We do use them to protect the camera's lens from scratching,
fingerprints or dirt. |
UXGA |
Refers to an image
resolution size of 1600 x 1200 pixels. |
VCD |
Video Compact Disc"
A CD-ROM disc that contains video and audio. Typically, a VCD can
hold about 74 minutes (650MB) of video and stereo-quality audio.
The video and audio are stored in MPEG-1 format and follow certain
standards (White Book). VCD video quality is roughly the same as
VHS video.
VCD Video Parameters Settings
Frame Size: 352x240 (NTSC) or 352x288
(PAL)
Frame Rate: 29.97 frames/second (NTSC) or 25 frames/second (PAL)
Video Data Rate: 1152 kbps
Audio Settings: Stereo, 44.1kHz and 224kbps audio bit rate |
VGA |
Refers to an image
resolution size of 640 x 480 pixels. |
Video
Out |
Means the digicam has
the ability to output its images on television screens and monitors
using either NTSC or PAL format. |
Viewfinder |
The eye level device
you look through to compose the image. |
Vignetting |
A term that describes
the darkening of the outer edges of the image area due to the use
of a filter or add-on lens. Most noticeable when the zoom lens is
in full wideangle. |
White
Balance |
Refers to adjusting
the relative brightness of the red, green and blue components so
that the brightest object in the image appears white. See also "AWB"
|
Wide
angle |
The focal length that
gives you the widest angle of coverage. |
X3
Image Sensor |
Foveon's new image
sensor for digital cameras that captures red, green and blue data
at every pixel. Read the X3 press release for full details. |
xD-Picture
Card |
A new flash memory
card standard that was co-developed by Fujifilm and Olympus in mid-2002.
Rumored to be replacing SmartMedia which has stalled at 128MB. xD
is scheduled to go as large as 8GB in a form factor the size of
a postage stamp.
For more info click here. |
XGA |
Refers to an image
resolution size of 1024 x 768 pixels. |
ZLR |
Zoom Lens Reflex, a
term coined by Olympus to describe their fixed mount lens SLR type
cameras. An SLR camera has interchangeable lenses, a ZLR has a non-removeable
zoom lens. |
Zoom
Lens |
A variable focal length
lens. The most common on digicams has a 3:1 ratio (i.e. 35-105mm).
See "3x" and "Focal Length" |