Ok, assuming that you have bought your first (prosumer or dSLR) camera, and played with it for a while on auto (or program) setting, and usually the quality of the shots is more than satisfactory, however your creative side wants more. Go ahead and try out the Aperture priority mode (indicated as Av on Pentax, Canon or A on Sony, Olympus, Nikon, Panasonic & Fuji). Some of the basic compact cameras might not have that mode, so we recommend that you check your camera manual.
What is Aperture ?
Aperture is ‘the size of the opening in the lens when a picture is taken.’
When you hit the shutter release button of your camera a hole opens up that allows your cameras image sensor to catch a glimpse of the scene you’re wanting to capture. The aperture that you set impacts the size of that hole. The larger the hole the more light that gets in
– the smaller the hole the less light.
The aperture is expressed in ‘f-stops’. It is often referred to as f/number – for example f/2.8, f/4, f/5.6,f/8,f/22 etc. Moving from one f-stop to the next doubles or halves the size of the amount of opening in your lens (and the amount of light getting through). Keep in mind that a change in shutter speed from one stop to the next doubles or halves the amount of light that gets in also – this means if you increase one and decrease the other you let the same amount of light in – very handy to keep in mind).
The Aperture priority (Av, or A) mode allows you to manually take control of the aperture, while the camera automatically regulates shutter speed to ensure that the photo has been exposed properly (or simply put, that there is enough light). This allows you to take direct control of Depth of Field in your photos.
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 (see top example on the right).
Small (or shallow) depth of field means that only part of the image will be in focus and the rest will be fuzzy (bottom example). This can be handy when taking portraits, shooting flowers and wildlife, but can be applied to pretty much anything. Basically, it makes the object in focus stand out above the rest.
Aperture has a big impact upon depth of field. Large aperture (remember it’s a smaller number) will decrease depth of field while small aperture (larger numbers) will give you larger depth of field.
If you ever get confused just remember that the small f-stop number e.g. f/2.8 will give you much smaller DOF, and making your subject stand out from the background. See example below.
The first flower photo was taken at f/32, meaning large f-stop, and large DOF. Notice that the background is visible, and draws attention from the flower which is the subject. The second flower photo was shot at f/5 and consequently much smaller DOF. Notice that the background is gone, and that it accentuates the flower much more than in the previous example.
If you want to further enhance the effect, try using the telephoto lens at the max. zoom setting, or use the maximum zoom available at your prosumer digital camera.