Cosmorex SE Manual De Propietario

Your 58mm automatic standard lens has openings (
apertures) from f/2 to f/16. At f/2, the greatest
amount of light is transmitted to the film; at f/16,
the amount of light transmitted is least. Each
marked number represents a 50% change in light
transmitted.

The Aperture Ring (26) of your lens may be set
at any marked lens opening (f/2, f/2.8, etc.) or at
positions in between marked lens openings. If the
Exposure Meter Aperture Indicator Dial (20)
indicates a lens opening between two f/numbers
(lens openings), turn the lens to the in-between
position.

USING DEPTH-OF-FIELD FOR
GREATER SHARPNESS

All photographic lenses, when focused on a
given subject, will show some objects in front of,
and in back of, that subject more or less
sharply. This "zone" of extra sharpness is
called "depth-of-field", and varies with different
lenses; it's greatest with wideangle lenses, and
least with telephoto lenses. With any lens, you'll
find your depth-of-field is always greater (more
things in focus) at small lens apertures such as f/
11 or f/16, and lesser (fewer things in focus) at
larger lens apertures such as f/2.8 or f/2.
In most picture taking, this phenomenon is of no
particular importance, as the subject will, in most
cases, appear equally sharp at all lens openings.
However, the area of sharp focus or "depth-of-
field" does become important in certain situations.