Contax Tvs III - Basic Photographic Concepts

11. Basic Photographic Concepts
<Exposure>
When a picture is taken, the aperture value and shutter
speed adjusts the amount of light to the film.
<Shutter Speed>
The shutter in the camera controls the amount of light
that reaches the film by the length of time it stays open.
The time the shutter stays open is the shutter speed.
<Aperture Value>
The aperture in the lens controls the amount of light
going through the lens by becoming smaller or larger.
The size of the opening produced by the size of the
aperture is the aperture value.
The larger the aperture value, the smaller the opening.
<Film Speed(ISO Value)>
Film speed is measured by values determined by
ISO(the International Standardization Organization). A
small ISO value means lower sensitivity but finer grain
and higher image quality.
A large ISO value means high sensitivity. Such films can
be used in locations with poor ambient lighting or with
fast shutter speeds, but it has coarser grain and
therefore a slightly poorer image quality.
<Depth of field>
When a subject is in focus, not only the subject itself but
also some area in front and behind the subject will also
be sharp. The range between the nearest and farthest
point that is sharp is the depth of field.
© The depth of field increases with small apertures
and decreases with larger apertures.
@ The depth of field is larger for a distant subject and
smaller for a closer subject.
@ The depth of field is larger behind than in front a
subject in focus. A lens with a long focal
length(telephoto lenses) has a narrower depth of
field than a lens with a shorter focal length.
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