Contents
Digital Photography Basics
How to Choose a Shooting Mode
Special Shooting Modes
Digital Photo Light Settings
How to Focus Your Digital Camera
How to Deal with Shutter Lag
How to Use a Flash in Digital Photos
How to Use a Zoom Lens
How to Take Great Digital Photos
Common Digital Photo Pitfalls
How to Manage Your Digital Photos
How to Print Digital Photos
How to Share Digital Photos Online
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How to Use a Zoom Lens
Almost every digital camera comes with a zoom lens, which allows you to get a closer view of or broader perspective on your subject without requiring you to move at all.
- Zoom in: To get a closer view of your subject
- Zoom out: To pull back and capture more of a scene
Focal Length
When you zoom in or out, you change the lens’s focal length, the distance from the center of the lens to the surface of the image sensor when your camera is in
focus. Focal length is measured in millimeters and used to describe camera lenses. For instance, a 35mm lens has a focal length of 35 mm.
- The longer the focal length: The closer the lens brings you to the subject. Lenses with focal lengths of more than 100 mm are called telephoto lenses.
- The shorter the focal length: The more of the scene the lens can capture. Lenses with focal lengths below 35 mm are called wide-angle lenses. Lenses with extremely short focal lengths (10–14 mm or so) are called fish-eye lenses because they can capture an extremely wide perspective.
Zoom lenses are described based on their range of focal lengths. A “17–40mm lens” can range in focal length from 17 mm to 40 mm as you zoom.
Adjust Focal Length to Zoom In or Out
Entry-level digital cameras usually include a lens that ranges from wide-angle to telephoto (30–300mm is a common range). To adjust the focal length, move a lever or dial
on the top of the camera: one direction zooms in (often indicated by a T for telephoto), and the other zooms out (often indicated by a W for wide angle). If you’re using a
detachable lens (as on a digital SLR), zoom in or out by turning the body of the lens.
Lens Distortion
Wide-angle and telephoto zoom lenses can create visual distortions at their extreme focal lengths. For example:
- Very short focal lengths: Can make objects at the edges of photos appear stretched out at odd angles
- Very long focal lengths: Can make objects in the background appear closer than they actually are
To prevent distortions, avoid using your camera’s lens at its extremes.
Optical Zoom vs. Digital Zoom
Digital cameras often include two types of zoom: optical zoom and digital zoom. Optical zoom is a mechanical zoom that actually changes the focal length of the lens. Digital zoom is an artificial zoom effect created by magnifying the pixels in an image to make it look as though you were closer to the subject than you actually were when you took the picture. Digital zoom creates a severe loss of image quality, so it’s best not to use it.
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