http://saraebyphotography.edublogs.org/camera-modes/
Aperture
Background sharpness control and brightness
The higher the aperture the greater the
depth of field (more of your photograph
will be in focus). The lower the aperture
the smaller the depth of field (less area
in focus).
Lower aperture
When photographers talk about “closing
down” or “opening up” they are referring
to changing the aperture. closing down
means to let less light into the camera; in
other words, to go to a higher F-Stop.
Conversely, opening up means to let
more light in; in other words, to go to a
lower F-Stop.
Higher aperture
Blured background out of focus
Open up
Lower / wider aperture/ smaller #
The higher the aperture the greater the depth of field (more of your
photograph will be in focus). The lower the aperture the smaller the
depth of field (less area in focus).
When photographers talk about “closing down” or “opening up” they
are referring to changing the aperture. closing down means to let
less light into the camera; in other words, to go to a higher F-Stop.
Conversely, opening up means to let more light in; in other words, to
go to a lower F-Stop.