||The lens f-number (usually called an f/-stop) is a ratio determined by
dividing the diameter of the hole (aperture) in the lens body that lets
light in by the focal length of the lens. Since the ratio value
gets larger as the diameter decreases, a lower f-number allows more
light in than a larger one. Explained more completely in my article on low-light
||An out-of-calibration condition where the camera's focusing system
indicates focus, but the lens is actually focused slightly In front of
||Refers to imaging sensors that are approximately the same size and aspect
ratio as the standard 35mm film frame. 36mm × 24mm.
||This is a technique for adding a small amount of flash to a scene to
balance the subject against the ambient light. Often used to compensate
for back-lighting or to brighten up shadows on subjects that are lit
from the side or in bright sun.
||Fisheye lenses got their name from the simple fact that the front
element of the lens bulges out to the point of being almost a
half-sphere, making it look like a fish's eye. These are
specialized wide angle lenses that usually provide a full 180° field of
view. Because no effort is made in the design to correct for
distortion, the images taken with these lenses are very distorted
with straight lines curved heavily outward, especially toward the edges.
Originally developed for taking pictures of the entire sky to record
cloud formations for meteorological studies, they are now used to make
images where the extreme distortion can provide an artistic effect.
||Technically, the distance from the nodal point of a lens to the focal
plane when the lens is focused to infinity. Practically, it denoted the
relative magnification of a lens with approximately 50mm equaling what
the human eye sees, or 1x. Longer lenses magnify (300mm = 6x) and make
objects seem closer. Shorter lenses give a wider view (24mm = .5x).
||This is a standard developed jointly between Kodak, Olympus, Panasonic
and through Panasonic, Leica to provide a designed-for-digital format
that would allow for compact, fully-functional DSLRs
that use a defined sensor size and could interchange lenses between
manufacturers via a standard mount. The name comes from the agreed-upon
standard sensor's aspect
ratio that is 4:3 which is similar to most P&S cameras rather than a
typical DSLR which
has a 3:2 aspect like 35mm film.
||The fixed plane in a camera's design where the image transmitted through
the lens is rendered in focus. The sensor or film is always mounted at
the Focal Plane. On most advanced cameras it is identified on the top of
the body with a ɸ symbol.
||Frames Per Second
||The number of images
a camera can capture every second, whether shooting stills or
||Fulltime Manual Focus
||Camera/lens setting that turns off autofocus completely and requires the
lens to be focused manually.
||Designation given to the highest tier of Minolta lenses. Now used to
designate the premium non-Zeiss Sony lenses.
||G-type Nikon lenses are designed for use with Nikon SLRs
where aperture is controlled from the camera body. The lack of an
aperture ring limits the backward compatibility with some older film SLRs.
||Equal to 1,073,741,824 bytes (closest exponent of two to one billion).
Unit of measure commonly used to denote the capacity of computer-related media such as memory
chips or discs.
||High Dynamic Range
||A technique that uses two or more bracketed exposures of the same
subject and blends them to create a single image that covers a wider Dynamic
Range that the camera is capable of in a single shot. The result is
an image that has detail in both the bright and shadowed areas and is
thought to more closely represent what the human eye sees.
designation for lenses from their film era that were redesigned to take
advantage of later model's faster focusing capability.
||Sigma term for their in-lens motor technology
||Intelligent Contrast Correction
||Canon term for image dynamic
range enhancement technology implemented in their cameras that uses
software to balance the highlight and shadow exposure to more closely
represent how the human eye sees. i-Contrast applies the changes
automatically as the image is recorded or in the camera afterward if you
forgot to turn it on while shooting.
||A lens that focuses by moving smaller internal components rather than
the larger, heavier front elements.
||Sometimes referred to as EVIL Electronic Viewfinder, Interchangeable Lens.
A class of camera that uses a larger (DSLR-sized)
4:3 or APS-C sensor
in a compact camera body with an electronic viewfinder linked to the
camera's sensor. This eliminates the mirror box and allows for a much
smaller camera body with more compact lenses than with a DSLR.
Essentially, this is a Digicam like the Sony R1, Olympus C-8080 or
Minolta A2 with the ability to use an assortment of lenses. The Micro
Four-Thirds standard was based on this concept but Sony and
Samsung have decided to use APS-C sensors. Nikon chose the much
smaller CX sensor.
||Canon term for their lens-based image-stabilization technology
||International Organization of Standardization
||The American Standards Association (ASA) developed a scale that all film
makers could use to standardize the sensitivity of film. The ASA
standard was adopted by the International Organization of
Standardization and the rating was changed to ISO. Digital sensors rate
their sensitivity using the ISO film standard and use standard values
like ISO50, 64, 80, 100, 160, 200, 400, 800, 1600 and higher with each
increase doubling the sensitivity of the previous one.
||Intellegent Through The Lens
||This is Nikon's term for their advanced electronic flash technology. It
allows the camera to evaluate the exposure for the flash by using a
pre-flash and measuring the exposure before firing the main burst.