Week 1
What is shutter
speed?
The basic rule
of a Photographer to be learnt.
Shutter
speed is ‘the amount of time that the shutter is open’.
In
film photography it was the length of time that the film was exposed to the
scene you’re photographing and similarly in digital photography shutter speed
is the length of time that your image sensor ‘sees’ the scene you’re attempting
to capture. Shutter speed is measured in seconds – or in most cases
fractions of seconds. The bigger the denominator the faster the speed (ie
1/1000 is much faster than 1/30).
In
most cases, usual usage shutter speeds are 1/60th of a second or faster. This
is because anything slower than this is very difficult to use without getting
camera shake. Camera shake is when the camera is moving while the shutter is
open and results in blur in the photos.
While
using a slow shutter speed (anything slower than 1/60) tripod is needed or
some type of image stabilization (more and more cameras are coming with this
built in).
Shutter
speeds available on camera will usually double (approximately) with each
setting. As a result, it usually have the options for the following
shutter speeds – 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8 etc. This
‘doubling’ is handy to keep in mind as aperture settings also double the amount
of light that is let in – as a result increasing shutter speed by one stop and
decreasing aperture by one stop should give the similar exposure levels.
Some
cameras also give the option for very slow shutter speeds that are not
fractions of seconds but are measured in seconds (for example 1 second, 10
seconds, 30 seconds etc). These are used in very low light situations, in going
on special effects and/or when trying to capture a lot of movement in a shot.
Some cameras also gives the option to shoot in ‘B’ (or ‘Bulb’) mode. Bulb mode
lets you keep the shutter open for as long as you hold it down.
When
considering what shutter speed to use in an image you should always ask
yourself whether anything in your scene is moving and how you’d like to
capture that movement. If there is movement in your scene you have the choice
of either freezing the movement (so it looks still) or letting the moving
object intentionally blur (giving it a sense of movement).
For
the actual speeds for the image, the photographer should choose, and vary
depending upon the speed of the subject in the shot and how much amount of blur
wanted in it.( Darren R,
2014).
Introduction
to shutter speed - dPS (2006) Available at:
http://digital-photography-school.com/shutter-speed/ (Accessed: 20 July 2016).
What is aperture?
The aperture is a small set of blades in
the lens that controls how much light will enter the camera. The blades
create an octagonal shape that can be widened (photographers call it shooting
“wide open”), or closed down to a small hole. Obviously, if it was shot
with the aperture wide open, then more light is allowed into the camera than if
the aperture is closed down to only allow a tiny hole of light to enter the
camera.
So suppose a picture taken that is too
bright. How can it be fixed? Simply choose a smaller aperture. Aperture sizes are measured by f-stops.
A high f-stop like f-22 means that the aperture hole is quite small, and
a low f-stop like f/3.5 means that the aperture is wide open. The size of the
aperture controls more than the brightness or darkness of the picture, though.
The aperture also controls the
depth-of-field. Depth-of-field is how much of the picture is sharp, and
how much is blurry. If you want to take a picture of a person and have
the background be blurry, it is the shallow depth of field. If taking a
picture of a sweeping mountain vista, a small aperture size (high f-stop
number) so that the entire scene is in sharp focus.
(No Date) Available at:
http://improvephotography.com/photography-basics/aperture-shutter-speed-and-iso/
(Accessed: 30 August 2016).
