Using the exposure modes
Every digital camera on the market makes it easy to take quick-and-dirty snapshots using an automatic exposure mode. Automatic exposure is great much of the time, but when you want to get a little more creative you may need to adjust the exposure settings.
Usually digital cameras have automatic exposure modes as well as manual, priority, and program settings. Here’s what each of these settings does, and when you would want to use them:
- Automatic: In this mode, both shutter speed and aperture settings are selected by the camera to match the current lighting. Some digital camera automatic modes try to select the fastest shutter speed possible in order to minimize camera shake when you take a picture, while most choose something in the middle, a compromise between speed and depth of field. There’s generally nothing you can do to change the settings that the camera chooses when set to fully automatic, except for adjusting the exposure compensation (EV) to over- or underexpose the scene.
- Program: The program mode (usually indicated by the letter P on your camera’s dial or LCD display) is similar to an automatic mode. Although the camera selects both the aperture and shutter, on some cameras you can modify the camera’s selection by turning a dial or pressing a button. The effect: you can increase or decrease the shutter speed, and the camera will adjust the aperture to match. This is a good compromise between fully automatic operation and manual selection. Use this mode if you don’t want to worry about devising your own exposure values, but still want some say over the shutter speed or aperture.
The program exposure mode is often the best all-around setting for your camera. In this mode, the camera chooses a good exposure setting, but you can tweak the shutter speed. The camera will instantly compensate by changing the aperture setting, keeping the overall exposure the same.
- Shutter priority: Using this mode, you can dial in whatever shutter speed you like, and the camera accommodates by setting the appropriate aperture to match.
This mode is ideal for locking in a speed fast enough to freeze action scenes, or slow enough to intentionally blur motion.
- Aperture priority: Using this mode, you can dial in the aperture setting you like, and the camera accommodates by setting the appropriate shutter speed. Use this mode if you are trying to achieve a particular depth of field and you don’t care about the shutter speed.
- Manual: The manual mode (typically indicated with an M) is like an old-style
noncomputerized camera. In manual mode, you select the aperture and shutter speed on your own, sometimes with the help of the camera’s recommendation. This mode is best used for long exposures or other special situations when the camera’s meter is not reliable.
Choosing exposure modes and lenses in special situations
Every situation is a little bit different, but here are a few general guidelines that can get you started.
Portrait Photography
Taking pictures of people can be fun but intimidating. It’s hard to get a natural pose from people when they know they are being photographed. The best way to capture good portraits is to work with your subjects so they are a little more at ease. If you’re trying to capture spontaneous, candid moments, then back off and try to blend in with the background. If you’re trying to capture a fairly formal-looking portrait, you have a little more work cut out for you. It’s up to you as the photographer to put your subjects at ease. Talk to your subjects and get them to respond. If you can get them to loosen up, they’ll exhibit more natural responses and look better on film. Take pictures periodically as you pose your subjects to get them used to the shutter going off, even if it isn’t a picture you intend to keep.
The best way to capture portraits is typically with the medium telephoto lens: in the 35mm world, that would be about 100mm. It is also recommended to work in aperture priority mode. Aperture priority will allow you to change the depth of field quickly and easily as you frame your images. Specifically, good portraits have very shallow depth of field.
You want to draw attention to the subject of your picture, and leave the background an indistinct blur.
Action photography
Action photography is often considered the most exciting kind of photography, but it’s also the most demanding for both your technique and your equipment. As in all kinds of photography, you can no doubt take some great pictures with anything from a wide-angle lens all the way up to the photographic equivalent of the Hubble telescope. And wide-angle lenses do, in fact, have a role in action photography. But the essence of many action shots is a highly magnified immediacy, something you can only get with the telephoto lens.
The shutter priority setting on your digital camera was born for action photography. To freeze action, you’ll need to use a fairly fast shutter speed. Luckily, this higher shutter speed works to your advantage by opening up the aperture and diminishing the depth of field; this focuses the viewer’s attention specifically on your subject. On the downside, of course, focusing is more critical since the depth of field is more shallow.
In general, is recommended that you use the fastest shutter speed available to capture action.
On the other hand, you can use a technique called panning to capture the subject in good, sharp focus and keep the background as a motion blur. Panning is convenient both when you want to make a somewhat artistic statement about the subject’s motion and when you know the camera can’t muster up a fast enough shutter speed to freeze the motion the ordinary way.
Panning involves some effort on your part. To create a good pan, you need to twist your body in sync with the motion of the subject as you press the shutter release. Here’s how:
1. Position yourself where you can twist your body to follow the motion of the moving subject without having the camera’s line of sight blocked by something else.
2. Set the camera’s shutter speed for about 1/60. Feel free to experiment with this, but if you set the shutter speed too slow, you can’t capture the subject effectively—it blurs.
And if the shutter is too fast, you won’t get the pretty blur in the background.
3. Twist your body with the motion of the subject and track it through the camera’s viewfinder or on the LCD display. Press the shutter release and continue tracking the subject until after you hear the shutter close again. Just like in baseball or golf, ensure that you follow through the motion even after the shutter releases. That way, you don’t stop panning in the middle of the exposure. You may need to practice this a few times to get the shot right.
The farther away the background is, the less motion blur effect you’ll get. For best results, get close to the object and its background. If the background is too far away, the blur will be minimal and it’ll just look out of focus.
Nature and landscapes
Unlike action photography and portraiture that rely on telephoto lenses to compress the action into an intimate experience, landscapes typically work best with wide-angle lenses that allow you to include huge, expansive swaths of land, air, and sea in a single frame. Zoom out for best results most of the time, and adjust the camera’s exposure in aperture priority mode to get deep or shallow depth of field, depending upon what works best for the picture in question.
A few special kinds of nature shots warrant special mention here:
Photographing a waterfall or running stream: The two ways to capture running water in a photograph are with a fast, freeze-framing shot or with a longer exposure that blurs the water into a continuous stream effect. Both effects can look good, but the latter is better. The effect looks great, and it’s easy to do: you simply need to take a long exposure of the water.
Here’s how:
1. You need to ensure that your camera will give you a long exposure, on the order of a half second. You can get this by shooting in automatic mode in the early morning or late afternoon, or using a manual mode.
2. Set your camera on a tripod (the long exposure requires a steady support).
3. Compose the image and take the shot.
Shooting wildlife: Wildlife photography is like action photography; it typically takes a telephoto lens, fast shutter speed, and a tripod. Try to fill the frame as much as possible.
Dealing with shutter lag
Older digital cameras had a “shutter lag” that lasted nearly a second, but even the newest digital cameras have some lag.
Shutter lag happens because digital cameras have a veritable checklist of tasks to perform when you press the shutter release. Not only does the camera need to measure the distance to the subject and lock in the proper focus, but it has to measure the ambient light, calculate the best exposure, and lock in an aperture setting and shutter speed. It also has computer-like “housekeeping” chores to perform, like initializing the sensor chip, flushing buffers, and reading white level.
If your camera’s lag doesn’t bother you, fine. But if you want to minimize the lag, there are a few things you can do. The biggest time-saver is auto focus. If you pre-focus your picture, you can save valuable milliseconds of lag. If you’re more adventurous, you can also try pre-setting the camera’s white balance. If the white balance is set on auto, the camera will have to adjust the colors in the image each and every time you take a picture. Instead, you can use the camera’s menu to set the white balance for whatever lighting conditions you’re actually shooting in, such as daylight, night time, fluorescent, or incandescent lighting. Just remember to change the white balance for every new lighting situation you find yourself in.
to be continued