Digital cameras make it
easy to take a variety of great shots
without really knowing how a camera works.
There are settings that are preprogrammed
with different aperture, shutter speed, and
ISO for you. You can use the action,
portrait, and other shortcuts for some
rocking pictures. But if you want to
go beyond and have more control, you need to
learn what these three terms mean and how to
manually adjust them on your camera.
Each of the three
aspects of the triangle relate to light and
how it enters and interacts with the camera.
The three elements are shutter speed, ISO,
and aperture. Remember that a change in one of the elements will impact the others. This means that you can never really isolate just one of the elements alone but always need to have the others in the back of your mind.
Shutter
Speed
Shutter speed is defined most basically
as the amount of time that the shutter is open.
Shutter speed is measured in seconds - or in most cases fractions of seconds. The bigger the denominator the faster the speed (1/1000 is much faster than 1/30).
In most cases you’ll probably be using shutter speeds of 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 your camera is moving while the shutter is open and results in blur in your photos.
If you’re using a slow shutter speed (anything slower than 1/60) you will need to use a tripod.
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). To freeze movement in an image you’ll want to choose a faster shutter speed and to let the movement blur you’ll want to choose a slower shutter speed. The actual speeds you should choose will vary depending upon the speed of the subject in your shot and how much you want it to be blurred.
ISO
What is ISO? In
traditional film photography ISO was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films - 100, 200, 400, 800, etc.). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.
In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography - the lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds (for example an indoor sports event when you want to freeze the action in lower light) - however the cost is noisier shots. 100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots.
Most people tend to keep their digital cameras in ‘Auto Mode’ where the camera selects the appropriate ISO setting depending upon the conditions you’re shooting in but most cameras also give you the opportunity to select your own ISO also.
When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example - if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.
Situations where you might need to push ISO to higher settings include:
Indoor Sports Events - where your subject is moving fast yet you may have limited light available.
Concerts - also low in light and often ‘no-flash’ zones
Art galleries,
churches etc- many galleries have rules against using a flash and of course, being indoors, are not well lit.
Birthday
parties - blowing out the candles in a dark room can give you a nice moody shot which would be ruined by a bright flash. Increasing the ISO can help capture the scene.
Aperture
A very common question for a digital camera user or beginner is what is digital camera aperture? The primary function of a digital camera lens is to collect light. The aperture of the digital camera lens is the diameter of the lens opening and
is the equivalent of the iris of our eye.
Aperture size is
expressed as an f-stop. The lower the
number next to the f, the wider the aperture
and the more light that makes it into the
camera.
Inexpensive cameras usually have maximum aperture size of f5.6 or f8. Lenses with a wide aperture such as f1.4 are more expensive than one that has an aperture size of f4.
Maximum aperture is preferable to a small one for the reason that it gives the photographer more flexibility in the kind of pictures that can be photographed by him or her under the circumstances available. This also enables the photographers to use a faster shutter speed to freeze action. However, in digital cameras operating in auto mode the camera automatically selects a shutter speed and the appropriate aperture as per the requirements of the image or the photograph.
There are a number of results of changing the aperture of your shots that you’ll want to keep in mind as you consider your setting, but the most noticeable one will be the depth of field that your shot will have.
Depth of Field (DOF) is that amount of your shot that will be in focus. Large depth of field means that most of your image will be in focus whether it’s close to your camera or far away. Small depth of field means that only part of the image will be in focus and the rest will be fuzzy.
Your portrait mode is preset to a small
depth of field making the person clear and
the background blurred.
Try it
Of course all of
this means nothing if you do not know what
to do with it. And there is only one
way to learn--just do it. Get out your
manual (or find it online) and see how to
manually change your camera. Then sit
down and aim your camera at a tree.
Take a shot, change the settings, take
another shot, change the settings.
Write down each setting in order so you can
see them when you upload. See the
differences. Go back out and send the
kids or the dogs running across the yard and
do it all again. See what happens.
Head out at sunset and try it all again.
Shot and
info:
Camera: Canon EOS DIGITAL REBEL XT
Shutter
Speed: 1/250
Aperture: f/5.6
ISO speed: 200
And my layout:
Ride the
Wave by James Davidson.
Supplies:
All digital items from:
Kelsey's Room by Handmaid Designs and
ScrapStreet Spring Fresh Kit by Handmaid
Designs (this month's free kit!), Font:
Distressed Typewriter.
