The Shutter and the Aperture.
Of the various controls on your camera the aperture and
shutter controls are the ones which are going to give a lot of control over the
content of your finished photographs. It is important to understand from the
outset what they are each responsible for and how they affect each other. We
have already looked at how the aperture and shutter affect exposure and their
relationship in that context. As you, hopefully, know you can use many
combinations of shutter and aperture yet still retain the same exposure value,
so we are now going to take a look at the factors which will influence how you
will select a particular combination of shutter and aperture.
In a nutshell, the shutter controls movement, which can be subject movement or
camera movement (shake), and the aperture controls how much of the scene (from
front to back) will be in sharp focus. This area of sharpness is known as the
'depth of field'. Depth of field is actually influenced by two factors:
Aperture and focused distance.
Juggling.
Much of the use of aperture and shutter is juggling one with the other. If you
want a lot of depth of field you will have to select a small aperture. To
counter this you will have to select a shutter speed that will;
If you want to capture fast movment you will have to select a reasonably fast
shutter speed. To counter this you will have to select an aperture which will;
There will be many occasions where you will have to make compromises,
particularly if you are hand holding your camera. Shallow depth of field is
fine so long as the most important part of the suject is sharply focused and
some subject movement may also be acceptable but camera shake will consign just
about anything to the bin. Unless , of course, the picture is very newsworthy
or is of personal significance.
We will go on to look at the aperture shortly but first we will look at the
shutter, shutter speeds and the dreaded camera shake. It happens to everyone at
some point and you can't say 'I don't know what’s wrong , this has never
happened to me before'.