How to Use a Digital Camera
Our friends at Yankee have asked me to write a blog entry about how to use a digital camera. Initially, I was stumped — isn’t that like asking a chef to write a few words about how to use a stove? First, the subject is just so vast — there are many books devoted to understanding photography and cameras. Second, I have a niche that I know well — landscape photography and architecture lite — but not much interest in portraits, weddings, sports, astrophotography, or street shooting. In my cooking analogy, I have tried many kinds of cooking and baking, but now prefer to use mostly my microwave and grill.
If you’re reading this, I assume you’re a newbie, so we’ll talk about compact cameras. Even the basic compacts have a stunning array of features and each brand has its own jargon. In addition, each model has a zillion control buttons/dials, and the manufacturers put the controls in different places. So I’ll be writing in broad generalities.
First, we need to discuss how photography works. Automatic cameras are computers that produce good exposures in normal scenes: green trees, fall foliage, blue sky, brick buildings, and groups of people with varied clothing. You will need other settings if:
- the tone of your subject is not average — snow or nighttime scenes
- your subject is very near you — close-up flowers
- your subject is moving fast across the screen — most toddlers
Photography is all about capturing the right amount of light on film or a sensor. The “right” amount is controlled by three things: aperture size, shutter speed, and ISO. It’s like filling a bucket with water from a hose. If you have a big hose (wide aperture), the bucket will fill quickly (fast shutter speed). A small hose will take more time. And the size of the bucket (ISO sensitivity) will also determine how long it takes to fill. These three settings are balanced to control the light, but each of them has side-effects that you should know about.
Aperture is the opening that lets light in. It’s like the pupil of your eye — if it’s open wide, it lets in a lot of light; if the aperture is narrow, it lets in less light. The other function of aperture is depth-of-field. Depth-of-field is the distance between you and the horizon that is in sharp focus. If the aperture is wide-open, the depth-of-field will be small. You see this effect in food photography, where only the front of the sandwich is sharp but the chips on the back of the plate are blurry. Usually, landscape photography is shot with an extensive depth-of-field, while close-ups of birds are shot with a narrow depth-of-field.
Shutter speed controls the length of time the shutter is open. With a still subject and a motionless camera (using a tripod), you won’t see much difference between a slow and fast shutter speed. But subjects move! If you’re taking a picture of a race car driving across your frame, a fast shutter speed will freeze the action sharply, and a slow shutter speed will make the car look blurred. Fast shutter speeds are usually chosen for sports, and slow shutter speeds are often used to make running water look silky. You can explore and practice the effects of changing shutter speed with the cars on your street. When you get good at capturing them, you could graduate to shooting Nascar or eagles in flight.
ISO is the sensitivity of the sensor to light. In film days, ISO measured how much light-sensitive silver was in the film; now it’s just another setting. A high ISO makes the camera more sensitive to light, but also creates “noise” in the pictures. You’ll see this noise in the shadowed or dark areas of your picture — it looks like little multi-colored dots. To avoid noise, use a lower ISO setting.
Automatic mode balances aperture, shutter speed, and ISO to provide a good exposure for average lighting in normal conditions. I use those adjectives intentionally: good, average, and normal. Automatic mode does not give excellent exposures for unusual light in problematic conditions. You can photograph a wide variety of subjects on automatic, and I use this mode a lot.
S, A, and M settings are used by more experienced photographers who want more control of the camera.
- S controls the shutter speed, and the camera will adjust the aperture to get a good exposure. Use this mode when you want to control the speed for situations like sports action, birds in flight, or running water.
- A controls the aperture, and the camera will adjust the shutter speed. Use this mode when you want the whole scene to be in focus or when you want only a tiny bit of it to be sharp.
- M lets you have full control of both aperture and shutter speed. You could use this mode for star trails.
Scene modes optimize the camera’s settings for various conditions. These settings are a great way to get good results without becoming Ansel Adams. All you have to do is to think about what the situation is and choose the appropriate scene mode. Here are some common examples: