When 35mm film cameras were king, exposure was an incredibly important subject.
The digital era has brought us light- years forward because we can now see the result of our settings instantly. Just as with film cameras, the DSLR takes into account the brightness of the subject, the contrast, the colour of the picture, and the area focused. When set for automatic exposure, the camera calculates all this and much more instantly.
Automatic exposure is useful, providing that you review your pictures on the LCD screen on the back of your digital camera as you shoot. If you are a newcomer to photography, there are many other different aspects that have to be considered before you take each picture. How do I frame the picture? Is it in focus? What is the background like? Until all these elements start to become second nature, it’s wise to leave your camera on auto-exposure. This will give you one less thing to worry about while you concentrate on all the others. Then slowly, as you become more technically proficient and have learned to hold the camera the right way, you’ll start to appreciate the small adjustments that are possible on your camera to perfect exposure.
On most DSLRs and high-end compact digital cameras, you have the option of overriding your automatic exposure and setting the exposure manually. This is where we begin to play with the camera’s settings. We will learn not only to expose correctly but to overexpose and underexpose deliberately.
Film photography requires you to change films if you want to change the ISO setting. Digital photography, on the other hand, allows you to shoot a group of pictures, or even a single picture, at one ISO setting, then change the ISO setting on the same memory card and keep shooting. You can change the ISO as often as you like.
Shutter speeds—Here are some basic tips about shutter speeds to begin:
To stop a racing car, or someone riding a bicycle, start with 1/1000 second. A good basic starting point for sports action.
For everyday pictures such as portraits and views, use speeds of 1/60 second to 1/250 second. If the photo is blurry due to camera shake then up the shutter speed or use a tripod.
If the light is really bad, try not to go below 1/60 second, If you must, hold your camera very still and don’t expect to freeze any action.
Take some time and play with the shutter speed, practice shooting scenes with variety of shutter speeds on a sunny day, an easy way to do this is to set your camera to shutter prioitoyand let it take care of all the other settings automatically while you adjust the shutter speed for each shot, try slow shutter with moving cars for example then set the shutter speed faster for each shot . Review each shot.
Aperture (f-stop)—Here are some basic tips about f-stops:
As a general rule, f/5.6 gives a little bit of depth of field, provided the lens focal length isn’t too long, and is still wide enough to enable high shutter speeds.
If it gets really dark, don’t be afraid to open your aperture to its maximum aperture, for example, f/2.
If you need loads of depth of field, or you want a slow shutter speed, stop down to f/11 (when using a short lens) or f/16. If your picture looks a little bit lighter or darker than it should, take another, having adjusted the exposure. You can make your image lighter by increasing your exposure, or darker by decreasing it.
Exposure compensation setting—
If you find that your images consistently look better by underexposing by one stop, or by overexposing by half a stop, then use the exposure compensation setting to build this factor into the camera’s light metering. This enables you to under- or overexpose by up to three f-stops or full shutter speeds. This is normally indicated on your camera by a scale from +3 to -3 with either half or third stop increments. Once you set it, the camera will usually maintain the adjustment until you change it. Most professional photographers use the exposure compensation feature to fine-tune the meter of their camera. Read your camera manual for info on how to find and adjust the exposure compensation settings in your camera menu.
Take lots of different versions of each picture. When you have time and the subject permits, vary your exposures so you don’t miss important shots.
Ron Cartier is a professional photographer. Catch him at rcartier@mac.com
