Aperture
is the diameter of the opening through which the light enters and
exposes the film. The aperture is defined on camera by its f-stops
(…f2, f2.8, f4, f5.6, f8, f11, f16, f22…). The smaller the number
of the f-stop, the larger, or wider, the aperture is.
Shutter speed is how long the
shutter remains open while taking a photo. It usually ranges from
1 second to 1/1000th of a second. Obviously, the longer shutter
speed, the more light reaches the film.
|
aperture
|
f
22
|
f
16
|
f
11
|
f 8
|
f
5.6
|
f
4
|
f
2.8
|
|
shutter
speed
|
15
|
30
|
60
|
125
|
250
|
500
|
1000
|
The above combinations
let the same amount of light to come through, because each stop
down combined with a longer shutter speed, and overall exposure
does not change
The question is, why we have different apertures and shutter speeds?
1. There will be situations in which one may want to vary the depth
of field; perhaps one is in a crowded city scene, and wants only
a single person in focus.
2. One may desire to use a certain speed. There are many reasons
for this- lack of light, too much light; one wants to stop motion
with a fast speed, or shows motion with a slow speed.
For either of the above reasons, one will need to know how aperture
and shutter speed work together. It will give one more flexibility
with his or her camera.
