All Photos by Mike Stensvold
Proper exposure is important. Color-print film has a lot of “latitude,” and digital images can be manipulated extensively, but a properly exposed image will always look better than a “corrected” poorly exposed one.
What is “proper” exposure, anyway? Well, it’s the exposure that gives you the result you want in your photo. With some subjects (sunsets and night scenes, for example), proper exposure is quite subjective: what one viewer deems perfect exposure, another will find too light or too dark. The idea is to come up with a method of exposing that will give you what you want in your photos on a consistent basis.
Digital cameras, of course, provide you with a big advantage: You can check the exposure before shooting (with consumer digicams) or immediately after (with digital SLRs), merely by glancing at the camera’s LCD monitor. At first, you’ll have to determine how well what you see on the camera’s LCD monitor matches what you see on your computer monitor after you download the images, and adjust accordingly if there’s a difference, but this exposure-checking ability is a tremendous boon.
Exposure Tips
1 Test your metering system
2 Understand how reflected- light meters work
3 Remember the basic daylight exposure
4 When in doubt, bracket
1 Test Your System
Probably the best way to learn how to expose scenes correctly with your camera (or hand-held meter) is take a roll or two of color slide film (because slide film has less tolerance for exposure errors than print film, and there’s no printing step to alter the results), and shoot subjects you’d normally shoot. Shoot each scene at the metered exposure, then shoot additional frames giving more and less exposure. When you get the film back from the lab, examine the results and decide which exposure produced what you wanted in each situation. Then you’ll know how to expose that situation next time you encounter it. You might be surprised to find that the multi-segment metering systems built into most of today’s AF 35mm and digital SLRs provide accurate exposures in a wide range of exposure situations.
2 Bracket Exposure
What you just did in item 1 is a bracketed series of exposures. It’s a good idea to shoot such a series any time you’re in doubt about the correct exposure: Shoot one frame at the exposure you think is right, then shoot additional frames, giving more and less exposure than that. With slide film, bracket in 1¼2-stop increments; with print film, full-stop increments should do. You’ll use more film, but you’ll assure that you get a properly exposed image.
3 Understand Your Meter
There are two basic types of exposure meter: incident-light, and reflected-light. Incident meters measure the light incident (falling) upon the scene; reflected meters (which are the type built into cameras) measure the light reflected from the scene.
Using an incident meter is simple: Hold it right in front of your subject, point its translucent hemisphere at the camera lens, and expose accordingly. The problems are (1) subjects that are in different light than where you are, and too far away to get to; and subjects that are light sources, such as fires.
Reflected-light meters are calibrated to reproduce the metered subject as an “average” medium tone. This is fine when your subject is indeed a medium-toned one. If the subject is brighter than a medium tone, the meter will see more light and thus call for less exposure (the meter doesn’t know what you’re pointing it at or how you want it reproduced in your photo; all it knows is how much light is striking its sensor). The result will be an underexposed (too-dark) bright subject and scene. Conversely, if the metered subject is darker than a medium tone, the meter will receive less light and thus call for more exposure; the result will be an overexposed (too-light) subject and scene.
The key to using a reflected-light meter is to remember this simple rule: Whatever you take the meter reading from will be reproduced as a medium tone in the resulting photograph. So, the simplest way to get good exposures with a reflected-light meter is to read medium-toned subjects. If you meter a bright subject, give more exposure than the meter suggests. If you meter a dark subject, give less exposure than the meter suggests. Ansel Adams’ Zone System is the most effective way to use a reflected-light meter (for black-and-white photography, anyway—it involves adjusting developing times to control contrast, and changing developing times with color films alters color balance as well as contrast), but just keeping the above rule in mind will suffice in most situations.
4. Extreme Contrast
When a scene’s brightness range exceeds the ability of your film or digicam’s image sensor to record detail throughout, you have to decide what’s most important—detail in the brightest areas, or detail in the darkest areas. Generally—especially when shooting slide film—you want detail in the highlights, because blown-out blank bright areas in a photo are very distracting. But for any given shooting situation, you have to consider what you want your photo to look like, and expose accordingly. Different films and digital-camera sensors have different dynamic ranges, so you have to experiment with your camera to see what it can handle.
5 Learn Your BDEs
If you’re shooting outdoors, the “basic daylight exposure” (BDE) rule of thumb can keep your exposures on track. The BDE states that for a front-lit subject in direct sunlight, the correct exposure is a shutter speed of 1¼ISO at f/16 (or equivalent): With ISO 100 film (or a digicam set to ISO 100), the basic daylight exposure would be 1¼100 at f/16 (or 1¼200 at f/11, 1¼400 at f/8, 1¼800 at f/5.6, 1¼1600 at f/4, etc.).
Switch to manual exposure mode, lock in the basic daylight exposure, and you’ll get correctly exposed subjects whether they’re medium tones, white or black—the meter can’t be “fooled,” because you’re not using the meter. If the subject is side-lit or in open shade, increase exposure one stop from the BDE. If the subject is backlit or the day is overcast, increase exposure two stops from the BDE. (And as always, it doesn’t hurt to bracket exposures if in doubt.)
