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Ambient
light – The natural light in a
scene.
Aperture
- A small, circular opening inside the lens that
can change in diameter to control the amount of
light reaching the camera's sensor as a picture
is taken. The aperture diameter is expressed in
f-stops; the lower the number, the larger the
aperture. For instance, the aperture opening when
set to f/2.8 is larger than at f/8. The aperture
and shutter speed together control the total amount
of light reaching the sensor. A larger aperture
passes more light through to the sensor. Many
cameras have an aperture priority mode that allows
you to adjust the aperture to your own liking.
See also shutter speed.
CCD
– Charge Coupled Device: one of the two
main types of image sensors used in digital cameras.
When a picture is taken, the CCD is struck by
light coming through the camera's lens. Each of
the thousands or millions of tiny pixels that
make up the CCD convert this light into electrons.
The number of electrons, usually described as
the pixel's accumulated charge, is measured, then
converted to a digital value. This last step occurs
outside the CCD, in a camera component called
an analog-to-digital converter.
CMYK
– Cyan, Magenta, Yellow, Black. The four
colors in the inksets of many photo-quality printers.
Some printers use six ink colors to achieve smoother,
more photographic prints. The two additional colors
are often lighter shades of cyan and magenta.
Depth
of Field - This is the area around the
focal point where the photograph is still in focus.
The larger the depth of field the more area around
the central focal point will be sharp or "in
focus". The depth of field is adjusted by
the camera's aperture setting.
Digital
camera – A camera that captures
the photo not on film, but in an electronic imaging
sensor that takes the place of film.
Downloading
– The process of transfering photos from
a camera memory card to the computer.
DPI
– Dots per inch: A measurement of the resolution
of a digital photo or digital device, including
digital cameras and printers. The higher the number,
the greater the resolution.
Exposure
- The amount of light that is received by the
recording material. The photograph's exposure
is determined by the camera's aperture and shutter
speed settings.
External
flash – A supplementary flash unit
that connects to the camera with a cable, or is
triggered by the light from the camera's internal
flash. Many fun and creative effects can be created
with external flash.
Fill
flash – A flash technique used
to brighten deep shadow areas, typically outdoors
on sunny days. Some digital cameras include a
fill flash mode that forces the flash to fire,
even in bright light.
FireWire
– A type of cabling technology for transferring
data to and from digital devices at high speed.
Some professional digital cameras and memory card
readers connect to the computer over FireWire.
FireWire card readers are typically faster than
those that connect via USB.
Focal
length - How far away from the camera
that the camera can have its point of focus.
Focus
- How clear items are in the picture or photo.
Many cameras come with an autofocus feature where
the camera finds the focal point for you usually
putting an indicator on the view finder. Often
you can turn off the autofocus and use a manual
focus where you turn the focus ring on the lens
until you reach the desired focal point.
Grayscale
– A photo made up of varying tones
of black and white. Grayscale is synonymous with
black and white.
Histogram
– A graphic representation of the range
of tones from dark to light in a photo. Some digital
cameras include a histogram feature that enables
a precise check on the exposure of the photo.
Image browser – An application that enables
you to view digital photos. Some browsers also
allow you to rename files, convert photos from
one file format to another, add text descriptions,
and more.
Image
resolution - The number of pixels in
a digital photo is commonly referred to as its
image resolution.
Inkjet
– A printer that places ink on
the paper by spraying droplets through tiny nozzles.
ISO
speed – A rating of a film's sensitivity
to light. Though digital cameras don't use film,
they have adopted the same rating system for describing
the sensitivity of the camera's imaging sensor.
Digital cameras often include a control for adjusting
the ISO speed; some will adjust it automatically
depending on the lighting conditions, adjusting
it upwards as the available light dims.
(you’ve probably seen them on films - 100,
200, 400, 800 etc).
The
lower the number the lower the sensitivity and
the finer the grain in the shots you’re
taking, producing more detail.
JPEG
– A standard for compressing image data
developed by the Joint Photographic Experts Group,
hence the name JPEG. Strictly speaking, JPEG is
not a file format; it's a compression method that
is used within a file format, such as the EXIF-JPEG
format common to digital cameras. It is referred
to as a lossy format, which means some quality
is lost in achieving JPEG's high compression rates.
Usually, if a high-quality, low-compression JPEG
setting is chosen on a digital camera, the loss
of quality is not detectable to the eye.
Lag
Time - The time it takes between when
you push the button to take a photo and when the
camera actually takes the photo. A long lag time
can be a big drawback to a camera.
LCD
- This the screen usually on the back of the camera
that allows you to view the photos you have taken.
The bigger the LCD the better idea you can get
of how your photo came out.
Megapixel
– Equal to one million pixels.
Panning
– A photography technique in which
the camera follows a moving subject. Done correctly,
the subject is sharp and clear, while the background
is blurred, giving a sense of motion to the photo.
Pixel
– Picture Element: digital photographs are
comprised of thousands or millions of them; they
are the building blocks of a digital photo.
RAW
– The RAW image format is the data as it
comes directly off the CCD, with no in-camera
processing is performed.
Red-eye
– The red glow from a subject's eyes caused
by light from a flash reflecting off the blood
vessels behind the retina in the eye. The effect
is most common when light levels are low, outdoor
at night, or indoor in a dimly-lit room.
Resolution
- This is term used for digital photos. The resolution
refers to how many pixels a photo contains. The
more pixels the higher the resolution. The higher
the resolution, the better quality of the photograph,
but also the more storage it will take up.
RGB
– Red, Green, and Blue: the three
colors to which the human visual system, digital
cameras and many other devices are sensitive.
Saturation
– How rich the colors are in a
photo.
Sensitivity
– See ISO speed.
Sensor
- The recording medium for digital cameras. The
sensors are made up of pixels. The more pixels
the higher resolution of photo the camera can
take.
Sharpness
– The clarity of detail in a photo.
Shutter
speed – The camera's shutter speed
is a measurement of how long its shutter remains
open as the picture is taken. The slower the shutter
speed, the longer the exposure time. When the
shutter speed is set to 1/125 or simply 125, this
means that the shutter will be open for exactly
1/125th of one second. The shutter speed and aperture
together control the total amount of light reaching
the sensor. Some digital cameras have a shutter
priority mode that allows you to set the shutter
speed to your liking. See also aperture.
Storage
card - A digital camera term referring
to the memory card where the digital photos are
stored. There are several standard types of memory
storage cards including Compact Flash, Memory
Stick, Smart Media, and xD.
Time
Lapse - Some cameras allow you to program
the camera to take a certain number of photos
with a programmed time interval between photographs.
Time lapse photography is often used to record
something happening over a long period of time
like a storm forming.
USB
– Universal Serial Bus: a protocol
for transferring data to and from digital devices.
Many digital cameras and memory card readers connect
to the USB port on a computer. USB card readers
are typically faster than cameras or readers that
connect to the serial port, but slower than those
that connect via FireWire.
White
balance – A function on the camera
to compensate for different colors of light being
emitted by different light sources. |