The Lingo
Reading the manual, talking to photographers, or surfing photo sites is enough to make a newbie photographer's head spin. All the jargon is difficult to make sense of, but if you know a few handy phrases you can sound like a pro. Here is a quick primer on the basics of digital photography terminology:
Aperture
The lens opening, which permits
light to expose the CCD on a digital camera or film (in a traditional camera). The aperture size is either fixed or
adjustable, and is calibrated in F-Stop numbers; the larger the number, the smaller the lens opening.
Bokeh
Bokeh describes the rendition of
out-of-focus points of light. It describes the appearance or "feel" of out-of-focus backgrounds and foregrounds.
Depth-of-field (DOF)
Refers to how much of the photo is sharp behind and in front of the main subject you are focusing on. It is mainly determined
by the size of your aperture as well as the focal length of the lens. The more or deeper the DOF the more in focus everything
in
the picture will be. Landscape photography tends are high depth-of-field shots. Smaller apertured and shorter focal
lengths give you deeper DOF. Similarly less or more shallow depth-of-field means that your main subject is in focus, but
the foreground and background tend to be out of focus. You usually want less DOF when taking portraits, close-ups or
macro shots. The wider the aperture (lower the f-stop) and the longer the focal length, the more shallow the depth of
field.
f-stop
A number that indicates the size of the lens aperture
(opening). The common f-numbers on 35mm cameras are f1.4, f2, f2.8, f4, f5.6, f8, f11, f16, and f22. The larger the f-number,
the smaller the lens opening, f22 is the smallest in this series. Also called the aperture, they work in conjunction with
shutter speeds to indicate exposure settings. The number sequence is printed on the lens barrel, each higher f number halves
the exposure of the preceding one.
The f-number itself is effectively the number of times the aperture diameter will divide into the lens focal length. For example, f4 aperture diameter is one quarter the focal length (i.e. 25mm aperture diameter in a 100mm focal length lens).
Fast lens
A lens with a wide maximum aperture (f2.8
is a
fast lens in a 35mm telephoto design). Often used in low light situations or when a fast shutter speeds are always
required.
Focal length
The distance from the rear model
plane of a
lens to the focus point when the lens is focused at the infinity position. This is usually measured in millimeters (mm). The
principal focal point is the position of best focus for infinity. There are two principal focal points, if a lens is turned
around a second focus is obtained. 'Reversed' lenses are often used in close-up Macrophotography because using a lens reversed
allows a closer focusing distance.
ISO (International Standards Organization)
Film ratings,
expressed as a number indicating a film's sensitivity to light. The larger the number, the more sensitive and faster the film
is. While traditional cameras don't have a specific ISO rating, digital cameras do as a way to express their sensitivity to
light. ISO is equivalent to ASA.
Increased sensitivity to light also amplifies noise making pictures grainier. Improvements in sensor technology are steadily reducing the noise levels at higher ISOs, especially on higher-end cameras. And unlike conventional film cameras which require a change of film roll or the use of multiple bodies, digital cameras allow you to instantly and conveniently change the sensitivity depending on the circumstances.
RAW
An unprocessed digital file direct
from
the camera. Not a 'standard' file format like TIFF or JPEG. Usually the camera manufactures software or 'plug-in' must be used
to open a RAW image file. RAW files are usually used to obtain the best theroetical quality from a given camera.
Shutter speed
The time in which the
shutter stays open to light, measured in fractions of seconds, (1/8000th a second is a very fast shutter speed and 1/2 second
is very slow).
SLR, or
Single-Lens-Reflex
A user looking through the
viewfinder on this type of camera actually looks through the picture-taking lens, thanks to a series of mirrors and prisms
within the camera. This is a very improved type of viewfinder, because what you see is what is in the actual picture
frame.
White Balance
The
camera's ability to correct color and tint when shooting under different lighting conditions including daylight, indoor and
fluorescent lighting. Most of the time people have their cameras set on AWB or Auto White Balance.
Wide-angle lens
A camera
lens with a short focal length, such as 14mm or 24mm allowing the user to get up to 180 degrees of viewing (hence the
term wide angle).