The next in the “Basics of Digital Photography-Exposure Triangle” series after ISO is Shutter Speed. The shutter in a digital camera is a thin sheet that opens and closes for the designated time to allow light on the film or sensor. The shutter is opened when you press the shutter release button and closes once again to prevent light from reaching the film or sensor. Shutter Speed is nothing but the time the shutter remains open for taking a photograph.
The key concept is that the longer the shutter remains open (lower shutter speed), the greater the amount of light that is allowed into the camera. The faster the shutter closes (higher shutter speed), the smaller the amount of light that is allowed into the camera.
If you pull out your digital camera, you may find the following standard shutter speeds when you set the dial to Manual (M):
- 1/1000 (some models only)
Each increment roughly doubles the amount of light that enters the camera. The shutter speed is generally measured in fractions of a second. A shutter speed of “1000″ means that the shutter will open for 1/1000th of a second. Shutter speeds of 1 second and longer are generally marked with a ‘, or other similar mark, after the number. This means that 16′ on your camera’s display would stand for 16 seconds. You may also find a setting called “B” or “BULB”. This setting keeps the shutter open as long as the shutter release button is pressed.
Pre-Programmed Shutter Speeds
All automatic cameras that are available today have some pre-programmed shooting modes. Each shooting mode is pre-programmed to capture the best shot without having to worry about the three amigos – ISO, Shutter and Aperture. The Creative Zone (see figure) outlined on the dial basically allows you more options for manual adjustments, while the Basic Zone allows you fully automatic shooting for specific kinds of subjects. Let’s understand the Basic Zone in some detail first.
Portrait: The portrait mode sets the camera to automatically select a large aperture (small number) which helps to keep the background out of focus. This makes the subject stand out and blurs the details behind the subject. Portrait mode works best when you’re photographing a single subject. For best results, get closer to the subject or zoom in if you are using a zoom lens. It also makes the flesh tones and hair look softer.
Landscape: Use the landscape mode when shooting wide scenery. Landscape mode uses a small aperture to gain depth of field. The greens and blues also become more vivid and sharp with this mode. At times, I find using this mode the best choice when shooting landscapes with a zoom lens. Use the wide-angle end of the zoom as this will have objects near and far in focus and also adds breadth to the landscape.
Close-up: This mode tends to direct the camera’s focus to be nearer to the camera. It would shrink the aperture and restrict the camera to wide-angle in an attempt to broaden the depth-of-field. This helps to include closer objects. When taking photographs of flowers or small things up close, use this mode. One tip, move your position to include the subject behind a simple background if possible. This will stand-out the subject better.
Sports: To photograph a moving subject like a child running or a moving vehicle or for that matter, freezing something in time like a splash of water, use the sports mode. Action or sports mode increases the ISO and uses a faster shutter speed to capture action. Some DSLR support multiple bursts under this mode if you hold down the shutter button, continuous shooting (approx 3.5 shots per second) and auto focusing will take effect.
Night Portrait: This mode uses an exposure long enough to capture background detail with fill-in flash to illuminate a nearby subject. Tip: keep your subject within 5 meters (approx 15 feet) of your camera if you are using built-in flash. Also, use a tripod to avoid a camera shake.
Flash Off: In places where flash photography is prohibited, example museums use this mode. This turns the built-in flash off and adjusts the shutter and aperture automatically. Under low light situations, there are chances of a camera shake occurring so use a tripod. This mode is a good choice for doing candle light photography. For example, use this mode when there is low ambient light and a child is blowing out candles.
Once you have a better grip and understanding of your camera, the Basic Zone will seem child’s play and you would like to experiment further and shoot like a pro. Here is when the Creative Zone comes in.
Program Mode (P): This mode calculates both the shutter speed and the aperture. ISO setting can be either set manually or automatically. Higher-end cameras offer partial manual control to change the automatically calculated values, i.e., increasing aperture and decreasing shutter time. The difference between Program mode and Full Auto mode is that in program mode, only the exposure is automatic, while other camera settings (e.g., shooting mode, exposure compensation, flash) can be set manually; in Full Auto mode everything is automatic. It’s a good mode to start out with as you get to know your camera.
Aperture Priority Mode (A or Av): Also known as Av (Aperture Value). This mode allows you to control the aperture settings and the camera then automatically selects the appropriate shutter speed. Remember that changing the aperture affects the Depth-of-Field.
Shutter Priority Mode (S or Tv): Also known as Tv (Time Value). In this mode you can choose the shutter speed, the camera sets the aperture automatically. Since the aperture value for a particular shutter speed is fixed and these values are paired this remains as an advantage as you need not worry about the aperture settings. This mode serves best when you want to freeze the motion or induce a trail in the movement. To freeze an action, use a fast shutter speed such as 1/500 sec. to 1/4000 sec. To give an effect of movement, use a medium shutter speed such as 1/30 sec to 1/250 sec. The best subject to photograph using this mode is moving water. Use a slow shutter speed of 1/15 sec or slower to blur a flowing river or water fountain. Remember to use a tripod when shooting on slow shutter speed.
Automatic Depth-Of-Field (A-Dep): Also known as Auto-Depth of field. In this mode, the objects in the foreground and background will be in focus automatically. All the focus points (AF) will function to detect the subject and the aperture required to attain the necessary depth of field will be set automatically.
Manual (M): Also known as Manual Exposure. In this mode you can set both the shutter speed and aperture as desired. With flash, the flash exposure will be set automatically to match the aperture that was set. Tip: set the desired settings on your camera and point the camera to the subject. Press the shutter button half-way and see the exposure level indicator in the view finder. The exposure level slider will show if your settings are correct or need a correction. Ideally speaking this is the mode you need to aim to work on.
There may be other modes as well on your camera depending on the brand you chose. Hopefully, this article post has cleared a thing or two about the various scene modes (Basic and Creative) in your digital camera. Give each mode a try and note down the settings when you clicked the photograph. Analyze them and improve.